Neotectonic Activity in the Low-Strain Broken Foreland (Santa Bárbara System) of the North-Western Argentinean Andes (26°S) Arnous, Ahmad; Zeckra, Martin; Venerdini, Agostina Lia; Alvarado, Patricia Monica; Arrowsmith, Ramón; Guillemoteau, Julien; Landgraf, Angela; Gutiérrez, Antonio; Strecker, Manfred R. Uplift in the broken Andean foreland of the Argentine Santa Bárbara System (SBS) is associated with the contractional reactivationof basement anisotropies, similar to those reported from the thick-skinned Cretaceous-Eocene Laramide province of NorthAmerica. Fault scarps, deformed Quaternary deposits and landforms, disrupted drainage patterns, and medium-sizedearthquakes within the SBS suggest that movement along these structures may be a recurring phenomenon, with yet to bedefined repeat intervals and rupture lengths. In contrast to the Subandes thrust belt farther north, where eastward-migratingdeformation has generated a well-defined thrust front, the SBS records spatiotemporally disparate deformation along structuresthat are only known to the first order. We present herein the results of geomorphic desktop analyses, structural fieldobservations, and 2D electrical resistivity tomography and seismic-refraction tomography surveys and an interpretation ofseismic reflection profiles across suspected fault scarps in the sedimentary basins adjacent to the Candelaria Range (CR)basement uplift, in the south-central part of the SBS. Our analysis in the CR piedmont areas reveals consistency between theresults of near-surface electrical resistivity and seismic-refraction tomography surveys, the locations of prominent fault scarps,and structural geometries at greater depth imaged by seismic reflection data. We suggest that this deformation is driven bydeep-seated blind thrusting beneath the CR and associated regional warping, while shortening involving Mesozoic and Cenozoicsedimentary strata in the adjacent basins was accommodated by layer-parallel folding and flexural-slip faults that cut throughQuaternary landforms and deposits at the surface.

Yerba Mate as a Settler Crop: From the Decline of Old-Growth Trees to the Rise of Plantations; La yerba mate como cultivo poblador: Desde la decadencia de los yerbales nativos al auge de los yerbales implantados Zang, Laura Mabel Desde las políticas tendientes a lograr la preservación de los yerbales nativos en la segunda mitad del siglo XIX hasta la difusión de los yerbales implantados a comienzos del siglo XX, el proceso colonizador de la actual provincia argentina de Misiones estuvo estrechamente vinculado a la yerba mate. Después de la Guerra de la Triple Alianza (1865-1870), el Estado nacional comenzó a tener mayor conciencia sobre la ubicación estratégica de Misiones y un mayor conocimiento acerca de las riquezas en recursos naturales que poseía; esta situación desembocó en la creación del Territorio Nacional de Misiones en el año 1881 y en la implementación de políticas estatales tendientes a poblar el espacio a partir del arribo de inmigrantes europeos.; From the policies aimed at preserving old-growth yerba mate trees in the second half of the 19th century to the proliferation of plantations at the beginning of the 20th, the colonization of the present-day Argentine province of Misiones was closely linked to this crop. After the War of the Triple Alliance (1865-1870), the Argentine government became more aware of the strategic location of Misiones and expanded its knowledge of the bountiful natural resources the province possessed. This led to the creation of the National Territory of Misiones in 1881 and the implementation of government policies for colonization of the area by European immigrants.

Control for cooperative transport of a bar-shaped payload with rotorcraft UAVs including a landing stage on mobile robots Gimenez, Javier; Salinas, Lucio Rafael; Gandolfo, Daniel; Rosales, Claudio Dario; Carelli, Ricardo This paper considers the cooperative transport problem of a cable-suspended rigid bar with two rotorcraft UAVs considering collision avoidance, weight distribution, and wind perturbations. The proposal is based on null-space theory and includes a landing stage where the load is settled down on a formation of ground robots. Therefore, a variable formation is considered according to the task phase. In order to simulate the proposal in a realistic environment, very complete dynamic models for UAVs, ground robots, and load are considered. An adaptation stage is incorporated to link the control actions with the inputs required by the dynamic models. Theoretical bounds for the errors are studied under the assumption that perfect velocity tracking is not fulfilled.

Motility and biofilm production involved in the interaction of phosphate solubilizing endophytic strains with peanut, maize and soybean plants Lucero, Cinthia Tamara; Lorda, Graciela Susana; Ludueña, Liliana Mercedes; Anzuay, María Soledad; Taurian, Tania Endophytic plant growth promoting bacteria are of great interest since the ability to colonize the internal tissues of plants gives it an adaptive advantage. To confer any beneficial effect on the plant, bacteria must present a successful colonization and thus be competent in the rhizosphere and finally infect internal tissues. In this sense, bacterial motility is an essential property involved in plant-microorganism interaction where bacteria can colonize the root and at the same time form biofilms. Within plant beneficial bacteria those that present phosphate solubilizing activity are of great interest due to the contribution of phosphorus to plants. The objective of this work was to evaluate the motility and biofilm formation properties of the strains Serratia sp. S119 and Enterobacter sp. J49 growing in the presence of peanut, maize and soybean root exudates. Results obtained indicated that both strains have flagella, possess swimming, swarming and twitching motilities and showed differential chemotactic attraction against root exudates. In addition, the strains under study showed the ability to form biofilms, being this ability greater in minimal media, in which a greater decrease was also seen by the addition of root exudates in the first hours of growth. The changes produced by the addition of root exudates in the chemotaxis and biofilm formation of the strains suggests that compounds released by the plants are detected by these bacteria and could be part of the molecular dialogue involved in their interaction with the roots of plant.

The paradoxical roles of inflammation during PD-1 blockade in cancer Hill, Marcelo; Segovia, Mercedes; Russo, Sofía; Girotti, Maria Romina; Rabinovich, Gabriel Adrián Recent studies have reported paradoxical roles of inflammation in tumor immunity triggered by PD-1 checkpoint antibody (Ab) blockade. Here, we elaborate on this controversy and propose a new perspective that might help understand this paradox. Since inflammatory cytokines and PD-1 blockade are known to target different subsets of exhausted CD8+ T cells, we propose that the timing at which anti-PD-1 Ab therapy and cytokine modulation occur might determine the fate of exhausted CD8+ T cells and perhaps, the clinical outcome of immunotherapeutic modalities.

Synthesis, UV-visible spectroelectrochemistry and theoretical characterization of new polypyridyl Ru(ii) complexes containing 2,4,6-tris(2-pyridyl)-1,3,5-triazine as precursors for water oxidation catalysts Domínguez, Sofía Eugenia; Moran Vieyra, Faustino Eduardo; Fagalde, Florencia In this work, we report the syntheses and physicochemical characterization of new chloro and aqua complexes of Ru(ii) with 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) and 2,2′-bipyridines substituted with donor and acceptor groups in the 4,4′-positions. The aqua complexes behave as precursors for water oxidation catalysts at pH = 1 using Ce(iv) as a sacrificial oxidant. Besides, the oxidized forms Ru(iv) and Ru(v) have been characterized at different pH values by electrochemistry, UV-Visible spectroscopy and spectroelectrochemistry. The reaction mechanisms were studied by combining mixing and stopped-flow experiments with spectrophotometric monitoring in the UV-visible region and all the rate constants were determined together with the corresponding TON and TOF values at pH = 1. Calculations based on Density Functional Theory (DFT and TD-DFT) were performed to support the experimental data.

Genetic Deletion of Galectin-3 Altered the Temporal Evolution of Macrophage Infiltration and Healing Affecting the Cardiac Remodeling and Function After Myocardial Infarction in Mice Cassaglia, Pablo; Penas, Federico Nicolás; Bettazza, Celeste; Fontana Estevez, Florencia Sofía; Miksztowicz, Verónica Julieta; Naya, Nadia Martínez; Llamosas, María Clara; Noli Truant, Sofia; Wilensky, Luciana; Volberg, Verónica; Cevey, Ágata Carolina; Touceda, Vanessa Michelle; Cicale, Eliana Magalí; Berg, Gabriela; Fernández, Marisa Mariel; Goren, Nora Beatriz; Morales, Maria Celina; González, Germán Esteban We studied the role of galectin-3 (Gal-3) in the expression of alternative activation markers (M2) on macrophage, cytokines, and fibrosis through the temporal evolution of healing, ventricular remodeling, and function after myocardial infarction (MI). C57BL/6J and Gal-3 knockout mice (Lgals3-/-) were subjected to permanent coronary ligation or sham. We studied i) mortality, ii) macrophage infiltration and expression of markers of alternative activation, iii) cytokine, iv) matrix metalloproteinase-2 activity, v) fibrosis, and vi) cardiac function and remodeling. At 1 week post-MI, lack of Gal-3 markedly attenuated F4/80+ macrophage infiltration and significantly increased the expression of Mrc1 and Chil1, markers of M2 macrophages at the MI zone. Levels of IL-10, IL-6, and matrix metalloproteinase-2 were significantly increased, whereas tumor necrosis factor-α, transforming growth factor-β, and fibrosis were remarkably attenuated at the infarct zone. In Gal-3 knockout mice, scar thinning ratio, expansion, and cardiac remodeling and function were severely affected from the onset of MI. At 4 weeks post-MI, the natural evolution of fibrosis in Gal-3 knockout mice was also affected. Our results suggest that Gal-3 is essential for wound healing because it regulates the dynamics of macrophage infiltration, proinflammatory and anti-inflammatory cytokine expression, and fibrosis along the temporal evolution of MI in mice. The deficit of Gal-3 affected the dynamics of wound healing, thus aggravating the evolution of remodeling and function.

Male Decapacitation Factor SPINK3 Blocks Membrane Hyperpolarization and Calcium Entry in Mouse Sperm Zalazar, Lucia; Stival, Cintia Estefanía; Nicolli, Anabella Rita; de Blas, Gerardo Andrés; Krapf, Dario; Cesari, Andreina Mammalian sperm acquire ability to fertilize through a process called capacitation, occurring after ejaculation and regulated by both female molecules and male decapacitation factors. Bicarbonate and calcium present in the female reproductive tract trigger capacitation in sperm, leading to acrosomal responsiveness and hyperactivated motility. Male decapacitating factors present in the semen avert premature capacitation, until detached from the sperm surface. However, their mechanism of action remains elusive. Here we describe for the first time the molecular basis for the decapacitating action of the seminal protein SPINK3 in mouse sperm. When present in the capacitating medium, SPINK3 inhibited Src kinase, a modulator of the potassium channel responsible for plasma membrane hyperpolarization. Lack of hyperpolarization affected calcium channels activity, impairing the acquisition of acrosomal responsiveness and blocking hyperactivation. Interestingly, SPINK3 acted only on non-capacitated sperm, as it did not bind to capacitated cells. Binding selectivity allows its decapacitating action only in non-capacitated sperm, without affecting capacitated cells.

Thymopentin improves the survival of septic mice by promoting the production of 15-deoxy-prostaglandin J2 and activating the PPARγ signaling pathway Zhang, Ye; Yang, Xue; Yan, Wenchao; Li, Rui; Ye, Qian; You, Linjun; Xie, Wenhao; Mo, Kun; Fu, Ruifeng; Wang, Yanxiang; Chen, Yufei; Hou, Hui; Yang, Yong; Birnbaumer, Lutz; Di, Qin; Li, Xianjing Sepsis, a systemic inflammatory response syndrome (SIRS) caused by infection, is a major public health concern with limited therapeutic options. Infection disturbs the homeostasis of host, resulting in excessive inflammation and immune suppression. This has prompted the clinical use of immunomodulators to balance host response as an alternative therapeutic strategy. Here, we report that Thymopentin (TP5), a synthetic immunomodulator pentapeptide (Arg-Lys-Asp-Val-Tyr) with an excellent safety profile in the clinic, protects mice against cecal ligation and puncture (CLP)-induced sepsis, as shown by improved survival rate, decreased level of pro-inflammatory cytokines and reduced ratios of macrophages and neutrophils in spleen and peritoneum. Regarding mechanism, TP5 changed the characteristics of LPS-stimulated macrophages by increasing the production of 15-deoxy-Δ12,14-prostaglandin J2 (15-d-PGJ2). In addition, the improved effect of TP5 on survival rates was abolished by the peroxisome proliferator-activated receptor γ (PPARγ) antagonist GW9662. Our results uncover the mechanism of the TP5 protective effects on CLP-induced sepsis and shed light on the development of TP5 as a therapeutic strategy for lethal systemic inflammatory disorders.

Estrés por calor: su efecto sobre el estado inmunológico de las vacas lecheras; Heat stress: its effect on the immune status of dairy cows Lendez, Pamela Anahí; Nieto Farías, María Victoria; Martinez Cuesta, Lucia; Vater, Adrian Alejandro; Ghezzi, Marcelo Daniel; Mota Rojas, Daniel; Dolcini, Guillermina Laura; Ceriani, Maria Carolina El estrés por calor constituye un desafío importante para la industria láctea. Los bovinos de raza europea (Bos taurus) están adaptados al clima frío, presentando características morfo-fisiológicas que los vuelven vulnerables al estrés por calor. El aumento de la temperatura global, del número de vacas lecheras de alta producción (VLAP) y la intensificación de los sistemas productivos puede afectar su potencial productivo, reproductivo y su sistema inmune. Por primera vez se evalúa el patrón de expresión de ARNm de TNF-α y sus receptores en animales expuestos a estrés por calor. La expresión de ARNm de esta citoquina proinflamatoria y sus receptores se realizó mediante la técnica de PCR en tiempo real (qPCR), en bovinos Holando Argentino, en Tandil, Argentina. Los animales se evaluaron durante un año, en tres períodos: primavera (n = 15), verano (n = 14) y otoño (n = 11). Se utilizaron los registros del Sistema Meteorológico Nacional de Argentina para estimar el índice de temperatura y humedad (ITH). Durante el verano se analizaron 609 eventos, 471 (77.33%) excedieron el umbral crítico de 72. En primavera, 6 de 537 eventos analizados (1.11%) superaron el umbral, y en otoño, ninguno de los 993 eventos tenía un ITH>72. Los resultados demuestran una disminución en la expresión de ARNm de TNF-α y sus receptores en animales expuestos a condiciones ambientales compatibles con diestrés durante 8,5±1,09 h diarias. Este diestrés produce efectos negativos en el sistema inmune, que podrían afectar la respuesta a vacunas y aumentar la susceptibilidad a infecciones oportunistas.; Heat stress constitutes a major challenge for dairyindustry. European breed cattle (Bos taurus) areadapted to low temperatures, with morpho-physiological characteristics that make them vulnerable to heatstress. The increase in global temperature, the numberof high production dairy cows, and the intensificationof productive systems might affect their productiveand reproductive potential, and immune system. Forthe first time, expression pattern of TNF-α mRNA andits receptors is evaluated in animals exposed to heatstress. Expression of this inflammatory cytokine andits receptors in Holando Argentino cows from Tandil,Argentina, was evaluated by real time PCR (qPCR).Animals were evaluated throughout a year, in threeperiods: spring (n=15), summer (n=14) and autumn(n=11). Data from the Sistema Meteorológico Nacionalfrom Argentina were used to estimate the Humidityand Temperature Index (HTI). During the summer, 609events were analyzed, and 471 (77.33%) exceeded thecritical threshold of 72. In spring, 6 out of 537 analyzedevents (1.11%) exceeded the threshold, and duringthe autumn season none of the 993 events had anHTI>72. Our results show a decrease in TNF-α and itsreceptors mRNA expression in animals in environmentalconditions compatible with distress along 8,5±1,09 dailyhours. This discomfort provokes negative effects inimmune system that could affect vaccine response andincrease susceptibility to opportunistic infections.

Reproduction and description of a new genus and species of deep-sea asteriid sea star (Echinodermata; Asteroidea) from the southwestern Atlantic Rivadeneira, Pamela Ruth; Martinez, Mariano I.; Penchaszadeh, Pablo E.; Brogger, Martin Ignacio Bernasconiaster pipi gen. et sp. nov. is described from work carried out in deep waters off Argentina. It is a small species with six arms, which has only cross-type pedicellariae, among other particular characteristics. Some specimens were found brooding their offspring in the oral area with their arms arched. Up to seven different stages of development were observed, each located at a particular location within the egg masses, and supported by an individual cord. These are connected to a central and more robust primary cord by an oral extension. Eggs were found in the gonads, the initial stages of development were located along the arms to the oral area and some stages were protruding from the mouth, into the everted stomach. A hermaphrodite specimen was found with both types of gonads (male and female). The information obtained suggests a reproductive period of at least five months, continued reproduction should not be ruled out. This species supports the hypothesis that brooding condition predominates in the deep-sea. The present study represents the first record of this type of reproduction in the deep waters of the Southwest Atlantic.

Ureide metabolism in Arabidopsis thaliana is modulated by C:N balance Lescano López, Ignacio; Devegili, Andrés Matías; Martini, Carolina; Tessi, Tomás María; González, Claudio Alejandro; Desimone, Marcelo Plants can respond and adapt to changes in the internal content of carbon and nitrogen by using organic compounds that widely differ in their carbon/nitrogen ratio. Among them, the amides asparagine and glutamine are believed to be preferred by most plants, including Arabidopsis. However, increases in the ureides allantoin and/or allantoate concentrations have been observed in different plant species under several environmental conditions. In this work, changes in the ratio between carbon skeletons and reduced nitrogen were investigated by varying the concentrations of nitrogen and sucrose in the growth media. Allantoin accumulation was observed when plants were grown in media with high ammonia concentrations. This increase was reverted by adding sucrose as additional carbon source. Moreover, mutant plants with a decreased capability to degrade allantoin showed a compromised growth compared to WT in ammonia supplemented media. Together, our results indicate that allantoin accumulation is induced by low carbon/nitrogen ratio and suggest that its degradation is critical for proper plant growth and development.

Sorghum pasta and noodles: Technological and nutritional aspects Palavecino, Pablo Martín; Curti, María Isabel; Bustos Shmidt, Mariela Cecilia; Penci, Maria Cecilia; Ribotta, Pablo Daniel Sorghum is a major cereal crop with various agronomic advantages, contains health-promoting compounds and is gluten-free. There is a growing tendency to use sorghum in pasta and noodle formulations, which are among the most widely consumed products in the world, but its potential benefits in human diet are not being fully exploited. Here we review research carried out during the past few years on the use of sorghum as the main ingredient or as an additive in pasta and noodles, highlighting its properties and production technology. Pasta and noodles can be produced with 5 to 100% of sorghum at laboratory, pilot or industrial scale with suitable cooking and textural quality coupled with distinctive sensory attributes. Cooking loss shows minimum values of 0.85 and 1.9 g/100 g for pasta and noodles, respectively, and high water absorption (up to 345 g/100 g). The interesting nutritional profile of the products generally includes up to 45% resistant starch (RS) and phenolic compound content with high antioxidant activity. In addition, tannins decrease starch digestibility 15–20%, producing low glycemic index (GI) products (below 65). This is especially important for celiac people, offering them the alternative of gluten-free sorghum pasta and noodles.

Jamming and percolation of linear k -mers on honeycomb lattices Iglesias Panuska, G. A.; Centres, Paulo Marcelo; Ramirez Pastor, Antonio Jose Numerical simulations and finite-size scaling analysis have been performed to study the jamming and percolation behavior of elongated objects deposited on two-dimensional honeycomb lattices. The depositing particle is modeled as a linear array of length k (so-called k -mer), maximizing the distance between first and last monomers in the chain. The separation between k -mer units is equal to the lattice constant. Hence, k sites are occupied by a k -mer when adsorbed onto the surface. The adsorption process starts with an initial configuration, where all lattice sites are empty. Then, the sites are occupied following a random sequential adsorption mechanism. The process finishes when the jamming state is reached and no more objects can be deposited due to the absence of empty site clusters of appropriate size and shape. Jamming coverage θ j , k and percolation threshold θ c , k were determined for a wide range of values of k ( 2 ≤ k ≤ 128 ). The obtained results shows that ( i ) θ j , k is a decreasing function with increasing k , being θ j , k → ∞ = 0.6007 ( 6 ) the limit value for infinitely long k -mers; and ( i i ) θ c , k has a strong dependence on k . It decreases in the range 2 ≤ k < 48 , goes through a minimum around k = 48 , and increases smoothly from k = 48 up to the largest studied value of k = 128 . Finally, the precise determination of the critical exponents ν , β , and γ indicates that the model belongs to the same universality class as 2D standard percolation regardless of the value of k considered.

Weaving people and places: Landscapes of obsidian circulation in NW Argentina. A long-term view (ca. CE 100–1436) Lazzari, Marisa; Sprovieri, Marina Leticia Ancient exchange practices have long been at the centre of comparative studies of social complexity. While finding valuable information, this approach has paid less attention to the multi-layered cultural understandings underpinning past transactions, ultimately diluting the power of archaeology to understand specific historical trajectories. This article examines the circulation and uses of obsidian in two sectors of the Calchaquí Valleys area of northwestern Argentina, considering contextual information from Early to Late Period (ca. CE 100–1436) settlements. Travelling far and widely, obsidian wove people and places in space and time through material interactions, condensing the broader regional world into partible materials for everyday use. While maintaining a generalised access ethos throughout the sequence, obsidian also enabled new forms of communal organisation and leadership. The article contributes to wider interdisciplinary approaches to the ontology of resources and their transformative social power, both in the Andes and beyond.

Efectos del Omega 3 ante Deterioro Cognitivo Castro Zamparella, Tatiana; Balaszczuk, Veronica El deterioro cognitivo puede ir desde olvido senil benigno hasta un deterioro cognitivo profundo. De esta manera la entidad clínica deterioro cognitivo leve (DCL) debe diferenciarse del deterioro de la memoria del envejecimiento normal, éste último está asociado a edad y refiere a quejas subjetivas de memoria y pruebas cognitivas. Los factores de riesgo para conversión de DCL a demencia es multifactorial, donde, la edad y genética son factores no modificables, mientras que por otro lado el riesgo cardiovascular, malnutrición, sedentarismo y fallas en la memoria episódica y semántica podrían ser consideradas factores de riesgo modificables para la evolución a Enfermedad de Alzheimer. En los últimos años, la investigación sobre las enfermedades neurodegenerativas ha dado resultados muy escasos en el tratamiento farmacológico convencional, no obstante los estudios preventivos poblacionales han sido muy alentadores. Estudios epidemiológicos demuestran que las dietas ricas en Omega 3 son asociadas con un menor riesgo de demencia y que los factores de riesgo detallados anteriormente pueden ser controlados manteniendo un estilo de vida saludable, basado en una dieta adecuada y ejercicio físico. En la Región y particularmente en Argentina, los estudios que exploran los efectos protectivos de los ácidos grasos Omega 3 son muy escasos, y los que existen hacen referencia a los mismos con referencia a patologías cardiacas o de hipertensión arterial. Entonces, teniendo enfrente un avance etario a largo plazo las tendencias en salud están puesta en prevenir y ganar el mayor tiempo posible para proporcionar calidad de vida a la población adulta.; Cognitive decline can range from benign senile forgetfulness to profound cognitive decline. In this way, the clinical entity mild cognitive impairment (MCI) must be differentiated from the memory impairment of normal aging, the latter is associated with age and refers to subjective memory complaints and cognitive tests. The risk factors for converting MCI to dementia are multifactorial, where age and genetics are non-modifiable factors, while on the other hand cardiovascular risk, malnutrition, sedentary lifestyle and failure in episodic and semantic memory could be considered risk factors modifiable for evolution to Alzheimer's disease. In the past years, research on neurodegenerative diseases has given few data in conventional pharmacological treatment, although population-based preventive studies have been very encouraging. Epidemiological studies show that diets rich in Omega 3 are associated with a lower risk of dementia and that the risk factors mentioned above can be controlled by maintaining a healthy lifestyle, based on an adequate diet and physical exercise. In the Region and particularly in Argentina, studies that explore the protective effects of Omega 3 fatty acids are very few, and those that exist refer to them with reference to cardiac pathologies or arterial hypertension. So, because aging population is advancing, health trends are set to prevent and save as much time as possible to provide quality of life for the adult population.

Cambios en la comprensión del propio rol de extensionista a partir de la experiencia: Un estudio latinoamericano; Changes in the understanding of the own role as extension worker as a result of experience: a Latin American study Landini, Fernando Pablo La extensión rural constituye una práctica altamente compleja. En general, la bibliografía académica ha estudiado los cambios históricos que han acontecidos en los enfoques de extensión. Sin embargo, poca atención ha recibido el estudio de los cambios en los enfoques de los extensionistas a lo largo de su trayectoria profesional. En esta investigación se describe de qué manera se transforma el modo en que los extensionistas comprenden su rol a partir de la práctica y la experiencia. Se entrevistó a 133 extensionistas de seis países latinoamericanos. Las entrevistas fueron transcriptas y sometidas a un análisis de contenido. Los resultados muestran que los extensionistas, como resultado de la práctica y la experiencia, tienden a (1) ampliar y complejizar su forma de comprender la tarea de extensión, (2) tomar conciencia de las limitaciones de sus propios conocimientos y propuestas, (3) adoptar enfoques más dialógicos y constructivistas, y a (4) ser progresivamente más realistas. En paralelo, se observa que los enfoques de extensión se articulan fuertemente con las identidades y con las emociones de los extensionistas, lo que explica que impulsar cambios en el modo de pensar la extensión sea una tarea altamente compleja.; Rural extension is a highly complex practice. In general, the academic literature has studied the historical changes that have taken place in the extension approaches. However, little attention has been given to the study of changes in the extension workers’ approaches during their career path. In this study, it aims to describe how extension workers change their understanding of their role as a result of practice and experience. A total of 133 extension workers from six Latin American countries were interviewed. The interviews were transcribed and their content analyzed. The results show that extension workers, as a result of practice and experience, tend to (1) broaden and make more complex their understanding of extension work, (2) become aware of the limitations of their own knowledge and proposals, (3) adopt more dialogical and constructivist approaches, and (4) become more realistic. Besides, the research also shows that extension approaches are highly intertwined with the identities and the emotions of the extension workers, which explains why contributing to changes in how they understand their role is so difficult.

Guidelines for the Analysis and Design of Argumentation-Based Recommendation Systems Leiva, Mario Alejandro; Budan, Maximiliano Celmo David; Simari, Gerardo Recommender systems study the characteristics of its users and applying different kinds of processing to the available data, find a subset of items that may be of interest to a given user in a specific situation. Argumentation-based tools offer the possibility of analyzing complex and dynamic domains by generating and analyzing arguments for and against recommending a specific item based on the users' preferences. This approach allows us to analyze the qualitative and quantitative characteristics of the recommended items, and to provide explanations to increase transparency. In this article, we develop a set of software engineering guidelines for the analysis and design of recommender systems leveraging this approach.

Evaluation of environmental and local factors on urban sarcosaprophagous Diptera: A case study with Sarcophagidae Battán Horenstein, Ariela; Mulieri, Pablo Ricardo; Gleiser, Raquel M. The urbanization process affects the structure of insect communities, favouring biotic homogenization processes by promoting adequate conditions for the establishment of synanthropic species. Considering the scarce knowledge about the ecology of Neotropical sarcophagids, we compared the flesh fly community from two different urban zones in two contrasting seasons and examined the response of the Sarcophagidae assemblage to landscape and microhabitat variables. Adult flies were collected in 13 sites with two traps (total number of traps 26) baited with 200 g of hydrated bone meal. A total of 2312 adult sarcophagids were collected belonging to 27 species; Oxysarcodexia paulistanensis (Mattos, 1919) represented >48% of the total sample. The local factor of insolation explained both the abundance and species richness of sarcophagids, collections being higher and richer in traps exposed to sun light compared with traps placed in the shade regardless of the season. Richness was also affected by the environment, being higher in traps exposed in suburban rather than urbansites. The combination of these factors (sub-urban environment and availability of openareas) could explain the Sarcophagidae assemblage. The average number of sarcophagidspecies collected was related to the season, providing a good opportunity to assess the temporal variability of this family in the region.

γ-ray/infrared luminosity correlation of star-forming galaxies Kornecki, Paula; Pellizza González, Leonardo Javier; del Palacio, Santiago; Müller, Ana Laura; Albacete Colombo, Juan Facundo; Romero, Gustavo Esteban Context. Nearly a dozen star-forming galaxies have been detected in γ-rays by the Fermi observatory in the last decade. A remarkable property of this sample is the quasi-linear relation between the γ-ray luminosity and the star formation rate, which was obtained assuming that the latter is well traced by the infrared luminosity of the galaxies. The non-linearity of this relation has not been fully explained yet. Aims. We aim to determine the biases derived from the use of the infrared luminosity as a proxy for the star formation rate and to shed light on the more fundamental relation between the latter and the γ-ray luminosity. We expect to quantify and explain some trends observed in this relation. Methods. We compiled a near-homogeneous set of distances, ultraviolet, optical, infrared, and γ-ray fluxes from the literature for all known γ-ray emitting, star-forming galaxies. From these data, we computed the infrared and γ-ray luminosities, and star formation rates. We determined the best-fitting relation between the latter two, and we describe the trend using simple, population-orientated models for cosmic-ray transport and cooling. Results. We find that the γ-ray luminosity-star formation rate relation obtained from infrared luminosities is biased to shallower slopes. The actual relation is steeper than previous estimates, having a power-law index of 1.35 ± 0.05, in contrast to 1.23 ± 0.06. Conclusions. The unbiased γ-ray luminosity-star formation rate relation can be explained at high star formation rates by assuming that the cosmic-ray cooling region is kiloparsec-sized and pervaded by mild to fast winds. Combined with previous results about the scaling of wind velocity with star formation rate, our work provides support to advection as the dominant cosmic-ray escape mechanism in galaxies with low star formation rates.