Houssay en IBYME recibe la visita de Ellen Braun, J. Hopper Jr y J.Sampson junto a Braun Menéndez y Luis F. Leloir En la fotografía: de izquierda a derecha Luis F. Leloir, Eduardo Braun Menéndez, J. Hopper Jr. (Univ. de California) Ellen Brown (Universidad de California), Bernardo Houssay y J. Sampson (Universidad de California) en IBYME, en ocasión del IV Congreso latinoamericano de Cardiología, reunido en Buenos Aires del 30/08 al 07/09 de1952 por la Sociedad Argentina de Cardiología.

A global record of particulated metals on the southwestern Atlantic shelf (Argentine Sea) Villagran, Diana Mariel; Fernandez Severini, Melisa Daiana; Truchet, Daniela María; Tartara, Matías Nicolás; Marcovecchio, Jorge Eduardo The Argentine Sea (Southwestern Atlantic) is one of the most productive ecosystem in the Southern Hemisphere. Research on metals in this region is scarce or null. In this study, we evaluated the concentrations of some metals in the suspended particulate matter (SPM), to provide baseline data that would enable us to understand the role of the SPM in the transport of metals in the Argentine Sea. Sampling was carried out during the austral summer 2016 at 20 stations distributed in the Argentine Sea. Surface seawater samples were collected and then filtered by vacuum through Millipore® HAWP 04,700 filters (0.45 µm). The samples were acid-digested (HNO3 and HClO4, 5:1) and the metal concentrations were determined with ICP-OES Optima 2100 DV (Perkin Elmer). Significant spatial variations were detected due to the extension of the study area, with the highest levels of metals in the stations next to large urban centers (Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn: 13.9, 154.9, 48.7, 54,470, 7646, 49.2, 58.6 and 509.5 μg g−1 d.w. respectively), which was supported by the nMDS and Cluster analyses. According to PCA analysis, two groups of metals that could have similar behavior were stablished: one group integrated by Cu, Zn, Pb and Ni, and the other group integrated by Cr, Fe and Mn. Metals that act as micronutrients and the toxic ones were present in all the sampling stations, highlighting the need to reinforce the study of these elements in this extensive and productive area of the South Atlantic Ocean.

Non-Stationary Power System Forced Oscillation Analysis Using Synchrosqueezing Transform Gill Estevez, Pablo Daniel; Marchi, Pablo Gabriel; Galarza, Cecilia Gabriela; Elizondo, Marcelo Anibal Non-stationary forced oscillations (FOs) have been observed in power system operations. However, most detection methods assume that the frequency of FOs is stationary. In this paper, we present a methodology for the analysis of nonstationary FOs. Firstly, Fourier synchrosqueezing transform (FSST) is used to provide a concentrated time-frequency representation of the signals that allows identification and retrieval of non-stationary signal components. To continue, the Dissipating Energy Flow (DEF) method is applied to the extracted components to locate the source of forced oscillations. The methodology is tested using simulated as well as real PMU data. The results show that the proposed FSST-based signal decomposition provides a systematic framework for the application of DEF Method to non-stationary FOs.

Effect of the application of compost as an organic fertilizer on a tomato crop (Solanum lycopersicum l.) produced in the field in the lower valley of the río negro (argentina) Pellejero, Graciela; Palacios, Julieta Romina; Vela, Emanuel; Gajardo Barriga, Omar Ariel; Albrecht, Luis Roberto; Aschkar, Gabriela Marisa; Chorolque, Amelia Amanda; García Navarro, Francisco J.; Jiménez Ballesta, Raimundo Purpose The main objective of the study was to evaluate the application of different doses of onion residue compost as mixtures with bovine manure as organic fertilizers for a round tomato crop planted in the field. Method The data were obtained experimentally in pilot fields. The experimental design was completely random-ized, with 4 m2 plots with ten plants each as an experimental unit and with three replications per treatment (2 years). Five treatments were tested, namely one unfertilized control, three with organic fertilization and one min-eral treatment. The variables measured were plant height (cm), stem base diameter (cm), fresh plant weight (g) and total dry matter (%). The parameters measured for the fruit were fresh fruit weight (g), fruit length (mm), fruit width (mm) and total soluble solids. Results The application of compost from the degradation of onion residues as mixtures with cow manure had posi-tive effects on the growth of the plant and on the development of tomato fruit. Compost doses of 60 Mg ha?1 and 80 Mg ha?1 gave similar values ​to chemical treatment and the control without fertilization was significantly lower than those with doses of organic and chemical fertilizer. These results indicate that this compost contains the nutrients required by the tomato crop for growth and development. Conclusion It was concluded that the agricultural use of quality compost is an effective strategy to obtain high quality products in an economically viable and environmentally sustainable way.

When Color Takes Shape: Young Children Use Object Information from Their Own Drawings to Solve a Task Vivaldi, Romina; Salsa, Analía Marcela In two studies, we examined whether and how 3- and 3½-year-old children were able to use object information from their own drawings to solve a task. The children had to produce drawings of simple objects and then use the shape and/or color of their pictures to identify replicas of the referents depicted. The results showed a relationship between graphic production and use. In Study 1, when shape was the single distinctive cue across objects, only the older group was able to produce and use drawings effectively. In Study 2, 3-year-olds used their drawings effectively when not only shape, but also color, were available as cues to identify the objects portrayed. Although most 3-year-olds’ drawings did not reflect the shape of the referents, by incorporating color young children demonstrated to recognize the intention behind their own representations and used them to solve the task. Our findings are discussed in line with intentionality and Theory of Mind.

Digital science in Latin America: Scope and benefits; La ciencia digital en América Latina: Alcance y beneficios del Castillo, Martín Guillermo; Arza, Valeria The use of digital tools is transforming scientific production processes and their impacts. In this article we evaluate to what extent digitalization in science has reached Latin American scientific activity and what have been its effects. For this purpose, we use bibliometric data from three medium-sized Latin American countries that have an important scientific trajectory: Argentina, Chile, and Colombia, focusing the analysis on four disciplines: biological and agricultural sciences, earth and planetary sciences, environmental sciences, and decisional sciences. We find that digitalization has been growing for the past 25 years, but the gap with leading countries has only narrowed slightly. Likewise, the incidence of digitalization varies by discipline. In terms of benefits associated with digitalization, our results show that articles that use digital science practices or tools have greater academic impact (have more citations), more collaboration (more co-authors), and more internationalization (authors from a larger number of countries). In other words, in these disciplines and in these countries, digitalization has managed to increase the visibility of research, potentially its quality and, thus, the social returns of the resources invested. Networks have also been expanded, thus promoting a better use of collective intelligence and the integration of local research problems into a global agenda, potentially increasing the resources devoted to research in these countries.; El empleo de herramientas digitales está transformando los procesos de producción científica y sus impactos. En este trabajo evaluamos en qué medida la digitalización en ciencia ha alcanzado a la actividad científica en América Latina y cuáles han sido sus efectos. Para eso, utilizamos datos bibliométricos de tres países latinoamericanos de tamaño medio, Argentina, Chile y Colombia, que tienen una trayectoria científica importante y el análisis lo hemos centrado en cuatro disciplinas: ciencias biológicas y agrícolas, ciencias de la tierra y planetarias, ciencias ambientales y ciencias decisionales. Encontramos que la digitalización ha ido creciendo durante los últimos 25 años, pero la brecha con los países líderes sólo se ha reducido levemente. Asimismo, la incidencia de la digitalización varía por disciplina. En términos de beneficios asociados a la digitalización, nuestros resultados muestran que los artículos que utilizan prácticas o herramientas de ciencia digital tienen mayor impacto académico (tienen más citas), más colaboración (más coautorías) y más internacionalización (autorías de un mayor número de países). Es decir, en estas disciplinas y en estos países, la digitalización ha logrado aumentar la visibilidad de la investigación, potencialmente su calidad y, así, los retornos sociales de los recursos invertidos. También se han ampliado las redes, propiciando de esta forma un mejor aprovechamiento de la inteligencia colectiva y la integración de los problemas de investigación locales a una agenda global, aumentando potencialmente los recursos que se destinan a la investigación en estos países.

Development and predation of Tupiocoris cucurbitaceus feeding on Tetranychus urticae Cuello, Eliana Marina; López, Silvia Noemí We evaluated the predatory bug, Tupiocoris cucurbitaceus as biocontrol agent of the two spotted spider mite, Tetranychus urticae, by analysing its predatory capacity, development to adult stage when fed on this pest, and the effect of predation on T. urticae population. T. cucurbitaceus was capable of killing spider mites although failed to fully develop when fed on them. A negative effect on the development of spider mite population was registered when T. cucurbitaceus was present. However, its own population decreased during the evaluated period and small nymphs were not recorded. Our results show that T. cucurbitaceus cannot control T. urticae when this is the only pest present.

Antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis: Systematic review and meta-analysis Molineri, Ana Inés; Camussone, Cecilia María; Zbrun, María Virginia; Suarez Archilla, Guillermo Alejandro; Cristiani, Mariana; Neder, Veronica; Calvinho, Luis Fernando; Signorini Porchietto, Marcelo Lisandro Staphylococcus aureus, one of the main contagious mastitis pathogens worldwide, is characterized for causing chronic intramammary infections that respond poorly to antimicrobial therapy, disseminating within the herd leading to high economic losses. The aim of this study was to determine the prevalence of phenotypic resistance to antimicrobial agents among S. aureus collected worldwide in the context of bovine intramammary infections between the years 1969−2020. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). One hundred and fifty-five articles were eligible for quantitative review. Most of studies included in this meta-analysis were from Europe (88), followed by Asia (56), Latin America (39), Africa (32), North America (26), and Oceania (8). The highest overall prevalence of resistant S. aureus was against penicillin (pestimate 0.451, CI95 % 0.415−0.487), followed by clindamycin, erythromycin, and gentamycin (p-estimate = 0.149, 0.085, and 0.069, respectively). Ceftiofur and cephalotin presented the lowest overall prevalence of antimicrobial resistance (AMR, p-estimate = 0.020 and 0.015, respectively). The AMR to almost all the antimicrobials evaluated presented an increasing pattern over time, more apparent from 2009 onwards. The antimicrobials with a higher increase in their AMR prevalence over time were clindamycin, gentamycin, and oxacillin. Africa, Asia and Latin America were the continents with higher AMR to most compounds included in this study. No differences in AMR were detected regarding the clinical origin of the isolates (subclinical vs clinical mastitis) for almost all antibiotics evaluated. Differences in the method for testing AMR (disc diffusion method vs minimum inhibitory concentration) and type of study design for monitoring AMR were detected underscoring the importance of these variables as critical factors to enable comparisons for evaluating emergence of AMR.

Antlion allometry suggests a greater importance of prey capture among first larval instars Farji Brener, Alejandro Gustavo; Juncosa Polzella, Agostina Silvia; Madrigal Tejada, Daniela; Centeno Alvarado, Diego; Hernández Soto, Mariana; Soto Huaira, Mayori; Gutiérrez Cruz, Sebastián First larval stages require adequate feeding to reach subsequent instars. However, the accumulation of reserves is also important in the last larval instar because it is vital to pupate and successfully perform metamorphosis into adulthood. We indirectly determined the presence of changes in the relative importance of prey capture through larval ontogeny in the antlion larvae (Neuroptera Myrmeleontidae), a sit-and-wait predator with three instar stages that capture preys that fall into their pit-traps. We used scaling relationships between the size of body parts directly related to prey capture (prothorax) versus those that are not (thorax + abdomen). The prothorax (neck, head, and mandibles) is used in the pit building, prey capture, and re-capture, and pit cleaning. We measured the body parts of 70 larvae of Myrmeleon crudelis in a tropical rain forest of Costa Rica. The prothorax showed negative allometry: it was proportionally larger in the first than in the last instars. These results support the growth hypothesis, which states that food acquisition is key in the earlier stages of larval development. First instars can be more food-limited than later instars because they build small pit-traps where only very small arthropods can fall; have smaller mandibles and relatively lower grab force, increasing the probability of the prey escaping; and have smaller fat reserves and thus, are unable to resist long periods of starvation. This illustrates the relevance of using scaling relationships to better understand how ecological pressures change along ontogeny, emphasizing the role of food acquisition at earlier ontogenetic stages.

Plant origin and fruit traits shape fruit removal patterns by native birds in invaded plant communities Martin Albarracin, Valeria Leticia; Amico, Guillermo Cesar Biotic interactions and mutualisms in particular have an important role in ecosystem structure and functioning as well as in the maintenance of biodiversity. Understanding how communities respond to the introduction of non-native species and what determines the establishment of novel interactions between native and introduced species will help in determining the potential impacts of biological invasions. The aims of this work were to assess patterns of frugivory and fruit removal in environments with invasion of non-native fleshy-fruited plants and to evaluate whether novel associations between native frugivores and non-native plants are determined by fruit traits. For this we selected eight study sites in areas with different degrees of invasion of non-native fleshy-fruited plants. In each site, we measured fruit availability and fruit traits of native and non-native plants. In addition, we conducted direct frugivory observations. We found that native and non-native fruits differed based on morphological trait variables, such as fruit weight and dimensions. Only two birds, Elaenia albiceps (smaller and migrant) and Turdus falcklandii (bigger and resident), are the main frugivorous present in the area. At the scale of the community of frugivores, neither visit nor fruit removal rates differ between natives and non-natives. However, at the species scale, while E. albiceps preferentially foraged on native plants, T. falcklandii preferred non-natives. Thus, some generalist frugivorous species like T. falcklandii can play a key role in promoting the invasion of non-native plants.

On the use of time windows for the determination of sound strength parameter G from uncalibrated room impulse responses measurements Accolti Mostazo, Ernesto Enrique; di Sciscio, Fernando The sound strength parameter G is one of the most important objective parameters related to the acoustical quality of concert halls, opera houses, and chamber music halls. G at mid frequencies is highly correlated with the acoustic quality reported by music conductors and subjects with musical training. Measuring this parameter requires a calibrated sound source or the direct sound isolated using a suitable time window as in [B. Katz, In situ calibration of the sound strength parameter G, JASA 138 (2) (2015) EL167–EL173]. In this article, the performance of several window functions and lengths used to isolate the direct sound is investigated. Although the errors obtained for low frequencies are large, an error in the order of a just-noticeable-difference at mid frequencies is obtained for a 30 ms Flat-Top window centered around arrival time of direct sound.

Is there a minimum number of landmarks that optimizes the geometric morphometric analysis of Mosquito (Diptera, Culicidae) wings? Beriotto, Agustina Carla; Garzón, Maximiliano Javier; Schweigmann, Nicolas Joaquin Culicids are the most significant arthropods affecting human health. Thus, their correct identification is critical. The use of Geometric Morphometrics (GM) has been recently incorporated into mosquito taxonomy and has begun to complement classic diagnostic techniques. Since sampling size depends on the number of Landmarks (LMs) used, this study aimed to establish the minimum number of wing LMs needed to optimize GM analysis of mosquito species and/or genera from urban and peri-urban areas of Argentina. Female left wings were used for the optimization phase, in which 17 LMs were reduced to four by iterative LM exclusion. To verify its efficiency, Principal Component Analysis (PCA), Discriminant Analysis (DA), and Canonical Variate Analysis (CVA) were performed. Additionally, a phenogram was constructed to visualize the results. We observed that five LMs for the PCA, CVA, and phenogram and nine for the DA enabled discrimination and/or clustering of almost all species and genera. Therefore, we tested the LM selection by using nine LMs and adding new species. The resulting PCA showed little overlap between species and almost all species clustered as expected, which was also reflected in the phenogram. Significant differences were found between wing shape among all species, together with a low total error rate in the DA. In conclusion, the number of LMs can be reduced and still be used to effectively differentiate and cluster culicids. This is helpful for better exploitation of available material and optimization of data processing time when classic taxonomy methods are inadequate or the material is scarce.

Rapid removal of fluoride from water usingcore@shell and @shell nanoparticles of SiO2@ZrO2 and @ZrO2. Investigation of the mechanismsinvolved and impact of elemental leaching Maisuls, Iván; Castro, Yolanda; Durán, Alicia; Larivière, Dominic; Arnal, Pablo Maximiliano El fluoruro es un contaminante natural del agua, el cual pone en peligro a muchas personas en todo el mundo cuando está presente en concentraciones superiores a 2 ppm. Aquí, la eliminación de fluoruro por cuatro partículas coloidales nanoestructuradas diferentes (SiO2@ZrO2nc, SiO2@ZrO2c, @ZrO2nc y @ZrO2c) se midió en sistemas estancos en un período de 24 h. Sorprendentemente, estos materiales eliminaron el fluoruro de las soluciones acuosas y alcanzaron el equilibrio en menos de 10 minutos. La combinación de una superficie específica alta y una rápida eliminación de fluoruro colocó a estos materiales entre los mejores actualmente conocidos en la eliminación de fluoruro. Además, se midió y cuantificó el impacto de la lixiviación de elementos. La influencia del tiempo, el pH y la concentración de fluoruro en la lixiviación de Zr y Si se evaluó con una metodología de superficie de respuesta. La lixiviación de Zr y Si continuó durante varias horas y dependió de coeficientes de primer orden, cuadráticos y de productos cruzados. Los estudios previos de eliminación de fluoruro con óxido de circonio a menudo asumían que una disminución en la concentración de fluoruro en la solución indicaba que el fluoruro estaba unido a la superficie del óxido. La solubilidad del óxido de circonio en agua es baja, pero no nula. Por tanto, Zr podría haber formado complejos fluorados solubles. Este es el primer reporte de eliminación de fluoruro con óxido de circonio que estudió la lixiviación del sólido para excluir la formación de fluorocomplejos solubles.; Fluoride is a natural contaminant of water – that endangers many people worldwide when present in concentrations higher than 2 ppm. Here, fluoride removal by four different nanostructured colloidal particles (SiO2@ZrO2nc, SiO2@ZrO2c, @ZrO2nc, and @ZrO2c) was measured in batch systems within a period of 24 h. Surprisingly, these materials removed fluoride from the water solutions and reached equilibrium in less than 10 min. The combination of high specific surface and fast fluoride removal placed these materials among the top materials currently known in fluoride removal. Also, the impact of element leaching was measured and quantified. The influence of time, pH, and fluoride concentration on leaching of Zr and Si was evaluated with a response surface methodology. Leaching of Zr and Si continued for several hours and depended on first-order, quadratic and cross-product coefficients. Previous studies of fluoride removal with zirconium oxide often assumed that a decrease in fluoride concentration in the solution indicated that fluoride was bound to the surface of the oxide. Zirconium oxide's solubility in water is low, but not zero. Hence, Zr might have formed soluble fluorocomplexes. This is the first report of fluoride removal with zirconium oxide that studied the leaching of the solid to exclude the formation of soluble fluorocomplexes.

Low-temperature lithium extraction from α-spodumene with NH4HF2: Modeling and optimization by least squares and artificial neural networks Resentera Beiza, Alexander Cristian Jesús; Esquivel, Marcelo Ricardo Oscar; Rodriguez, Mario Humberto In this research, an efficient method of lithium extraction from α-spodumene by thermal treatment with NH4HF2 was optimized. Temperature (T), α-spodumene:NH4HF2 molar ratio (m), and reaction time (t) were studied using a two-level univariate strategy. The results were modeled using least squares (LS) and artificial neural networks (ANN) and then compared to obtain a predictive model of the system. Both models showed good concordance with the experimental data (R² of 0.9881 and 0.9957, respectively) and with each other. The ANOVA of the cubic model indicated that T, m, t, and the interactions Tt, T², and T³ were significant. Finally, the system was optimized using response surface methodology to maximize Li extraction and minimize operational parameters. The desirability function predicted an extraction value of 95.48 ± 2.50% for T = 156.7 °C, m = 1:17.5, and t = 100.6 min. Experimental lithium extractions of 96.45 ± 3.68% were obtained at 157 °C using a molar ratio of 1:17.5 for 100 min. The products of the thermal treatment were LiF, (NH4)3SiF6·F, (NH4)3AlF6, NH3, and H2O. After a water leaching step, the silicon in the sample was separated, obtaining (NH4)3SiF6·F as a by-product. Finally, the solid products were leached with H2SO4 10% (v/v) to solubilize all lithium.

Regional Integration and Ceramic Consumption in the Border Region of Bolivia and Argentina (ca. AD 1000-1450) Echenique, Ester; Nielsen, Axel Emil; Avila, Maria Florencia; Gilstrap, William This article investigates the mechanisms by which different communities were articulated during the Late Intermediate period (ca. AD 1000-1450) in the Río Grande de San Juan Basin, also called the Chicha Region, located in the border region of Bolivia and Argentina. Through analyses of systems of pottery production, circulation, and consumption, we examine interaction networks, social integration, and alliance building at a regional level. Yavi-Chicha pottery from two sites in the Chicha Region-Chipihuayco, in the Talina Valley (Bolivia), and Finispatria, in San Juan Mayo (Argentina)-provide key insights into regional integration and constellations of practice through their localized technological style and shared consumption strategies. This study reveals that people of Finispatria incorporated the entire Yavi-Chicha-style household assemblage-partly produced in Chipihuayco, partly in Finispatria, or partly at some unknown location-into their everyday lives. We argue that the entire household ceramic repertoire of the study region played a fundamental and socially integrative role as it circulated across the region.

Immune checkpoints pathways in head and neck squamous cell carcinoma Veigas, Florencia; Mahmoud, Yamil Damián; Merlo, Joaquín Pedro; Rinflerch, Adriana Raquel; Rabinovich, Gabriel Adrián; Girotti, María Romina Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of tumors usually diagnosed at an advanced stage and characterized by a poor prognosis. The main risk factors associated with its development include tobacco and alcohol consumption and Human Papillomavirus (HPV) infections. The immune system has a significant role in the oncogenesis and evolution of this cancer type. Notably, the immunosuppressive tumor microenvironment triggers immune escape through several mechanisms. The improved understanding of the antitumor immune response in solid tumors and the role of the immune checkpoint molecules and other immune regulators have led to the development of novel therapeutic strategies that revolutionized the clinical management of HNSCC. However, the limited overall response rate to immunotherapy urges identifying predictive biomarkers of response and resistance to treatment. Here, we review the role of the immune system and immune checkpoint pathways in HNSCC, the most relevant clinical findings linked to immunotherapeutic strategies and predictive biomarkers of response and future treatment perspectives.

Spatial and temporal distribution of Persistent Organic Pollutants and current use pesticides in the atmosphere of Argentinean Patagonia Miglioranza, Karina Silvia Beatriz; Ondarza, Paola Mariana; Costa, Patricia G.; de Azevedo, Amaro; Gonzalez, Mariana; Shimabukuro, Valeria Mercedes; Grondona, Sebastian; Mitton, Francesca María; Barra, Ricardo O.; Wania, Frank; Fillmann, Gilberto XAD-based passive air samplers (PAS) were used to evaluate organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and some current use pesticides (chlorotalonil, trifluralin and dichlofluanid) in the atmosphere of Argentinian Patagonia. The PAS were deployed for 12 months during three consecutive years along a longitudinal (Rio Negro watershed) and a latitudinal (Patagonian coast) transect. Endosulfan, trifluralin and DDT-related substances were the most prevalent pesticides in the Rio Negro watershed, an intensive agricultural basin, consistent with ongoing use of endosulfan at the time of sampling. Concentrations of industrial contaminants were low (mean 25 pg/m3 and 1.9 pg/m3 for Σ38 PCBs, and Σ5PBDEs, respectively) and similar among sites. However, along the Patagonian coast, air concentrations of total contaminants were highly variable (14–400 pg/m3) with highest values recorded at Bahia Blanca, an important industrial area that is also downwind of the most intensively agriculturally used area of Argentina. Contaminant levels decreased toward the south, with the exception of the southernmost sampling site (Rio Gallegos) where a slight increase of total pollutant levels was observed, mainly due to the lower chlorinated PCB congeners. Interannual variability was small, although the last year tended to have slightly higher levels for different contaminant groups at most sampling sites. This large-scale spatial atmospheric monitoring of POPs and some CUPs in the South of Argentina highlights the important and continuing role of rural and urban areas as emission sources of these chemicals.

Teoría política crítica [esbozo programático]; Critical political theory program outline [program outline] Biset, Emmanuel El objetivo del artículo es presentar de modo programático qué puede entenderse por “teoría política crítica”. Me propongo dar lugar a esta definición en una serie de pasos: primero, analizando cuáles serían los “asuntos” de una teoría política crítica, o si se quiere, cuáles son los problemas y preguntas que se plantea; segundo, precisando los “modos” de ejercer esas preguntas, precisar lo que se podría llamar una metodología y mostrando cómo constituye una forma dela subjetividad. Desde estos elementos, el objetivo es proponer una definición de teoría política crítica destacando los problemas y desafíos que surgen allí.; The aim of the paper is to present in a programmatic way what can be understood by “critical political theory”. I intend to give rise to this definition in a series of steps: first, by analyzing what is the “matter” of a critical political theory would be, or, what the problems and questions are; second, by specifying the “ways” of exercising these questions, by specifying what might be called a “methodology” and by showing how it constitutes a form of subjectivity. From these elements, the objective is to propose a definition of critical politicaltheory highlighting the problems and challenges that arisethere.

Asistencia técnica y extensión rural a sectores subalternos del agro: Transformaciones y estrategias en el marco del Aislamiento Social Preventivo y Obligatorio; Technical assistance and rural extension to subaltern sectors of agriculture: Transformations and strategies in the framework of Preventive and Mandatory Social Isolation González Maraschio, María Fernanda; Marcos, Maria Florencia La actividad agropecuaria fue una de las pocas habilitadas en el marco del Aislamiento Social Preventivo y Obligatorio (ASPO) que se decretó en el marco de la pandemia por Covid-19 el 20 de marzo del 2020 en Argentina. Esta actividad, por sus características generales, queda al margen de las suspensiones o cambios que sí estuvieron presentes en otras ramas económicas. Parte del universo de productores en Argentina está constituido por un sector que desde las políticas estatales se denominan agricultores familiares y gran parte de este segmento es el que produce alimentos frescos para la población. Este sector también se constituye como beneficiario de asistencia técnica y extensión rural que brindan algunas instituciones tanto estatales como no estatales.En el siguiente artículo se busca describir y analizar los cambios y las continuidades de las actividades de asistencia técnica y extensión rural a la agricultura familiar por parte de agentes estatales y no estatales a través de los datos que se producen apartir de una encuesta diseñada y distribuida por las autoras. Se trata de una propuesta exploratoria y descriptiva en la cual se pueden vislumbrar diversas estrategias y modalidades que se han dado las/os extensionistas rurales en la organización del trabajo y en nuevas formas de vinculación tanto con los/as productores como con las instituciones.; Agriculture was one of the few enabled activities within the framework of the Preventive and Mandatory Social Isolation (ASPO) that was decreed in the Covid-19 pandemic on March 20, 2020 in Argentina. This activity, due to its general characteristics, remains outside the suspensions or changes that were present in other economic branches. Part of the universe of agricultural producers in Argentina are called family farmers, name that comes from state policies, and a large part of this segment produces fresh food for the population. This sector is also a beneficiary of technical assistance and rural extension provided by some state and non-state institutions. The following article aims to describe and analyze the changes and continuities of technical assistance and rural extension activities to family farming by state and nonstate agents through the data produced from a survey designed and distributed by the authors of this article. It is an exploratory and descriptive proposal in which it is possible to glimpse various strategies and modalities that rural extension workers have given themselves in the organization of work and in new forms of linkage with both producers and institutions.

The magnitude of behavioural responses to artificial light at night depends on the ecological context in a coastal marine ecosystem engineer Nuñez, Jesus Dario; Sbragaglia, V.; Spivak, Eduardo Daniel; Chiaradia, Nicolas Mariano; Luppi, Tomas Atilio Artificial light at night (ALAN) is one of the most extensive human geographic disturbances to wildlife. ALAN can have ecological and evolutionary effects on individual organisms, which in turn can affect populations, communities and ecosystems. Although understanding of the effects of ALAN on the ecology and biology of organisms has increased in recent years, most of these advances are in terrestrial environments, but scarce in marine habitats, especially in ecologically important transition areas such as saltmarshes. Here, we study the effects of ALAN on the behavioural budget (i.e. the proportion of time spent performing feeding, burrow maintenance and concealment) of the South American intertidal crab Neohelice granulata, which is an ecosystem engineer of coastal salt marshes. Moreover, we compared the impact of a gradient of ALAN between two different saltmarshes with contrasting environmental characteristics. Our results showed a relationship between ALAN and the behavioural budget. In particular, we showed that an increase in ALAN drove an increase in time spent maintaining burrows at the expense of time spent concealed in the burrow or feeding outside it. Such effects showed slightly different patterns in the two saltmarshes, possibly related to the reproductive value of burrows for mating and to predation risk. Considering the ecosystem role of N. granulata, we argue that the different effect of ALAN on its behavioural budget could have ecosystem effects that differ between the two saltmarshes studied here.