Ciencia y Tecnología
Seasonal acclimation of energy and water balance in desert‐dwelling rodents of South America
Cavieres, G.; Bozinovic, F.; Coronel, Betiana Melisa; Dacar, María Ana; Sassi, Paola Lorena
Seasonal changes in environmental conditions may induce reversible physiological adjustments in organisms. We studied the acclimatization for multiple stressors in energy expenditure and water balance in Galea leucoblephara, a diurnal hystricognath rodent native to South America that experiences significant changes in temperature, precipitation, and food availability among seasons. We conducted a field study in the Monte Desert of Mendoza, Argentina, where we evaluated adult individuals’ physiological status during two contrasting seasons in terms of climate and primary productivity. Reduced temperature, rainfall, and primary productivity during winter were associated with a decrease of 70% in basal metabolic rate (BMR), 30% in total evaporative water loss (TEWL), and 9% in body mass (Mb). In contrast, higher water availability, high temperature, and primary productivity during summer, induced significant increases in energy expenditure and evaporative water loss. As expected, the proportion of dietary items consumed by G. leucoblephara varied seasonally, resulting in a more diverse diet during summer. Our results illustrate how G. leucoblephara can cope with high seasonal contrasts in water availability, temperature, and food availability by modifying its physiological performance. Our data provide support for the hypothesis of physiological flexibility in energetic traits and water balance in response to the environmental challenges of the Monte Desert.
Development of antimicrobial starch-based composite films reinforced with soybean expeller for sustainable active packaging applications
Development of antimicrobial starch-based composite films reinforced with soybean expeller for sustainable active packaging applications
Berti, Sofia; Jagus, Rosa Juana; Flores, Silvia Karina
In this study, the influence of glycerol and sonicated soybean expeller (SSE) on composite edible films supporting natamycin and nisin was investigated using Response Surface Methodology. Assessments were conducted on mechanical properties, moisture content, water solubility (SW), and color. Optimal results were achieved with 0.46% SSE and 1.4% glycerol, yielding a maximum tensile strength (TS) of 1.0 ± 0.1 MPa and a minimum SW of 19.0 ± 0.3%. SSE had no impact on Tg values (82–89 °C), while antimicrobials reduced Tg (70–73 °C) due to increased water retention. Water vapor permeability was (2.5 ± 0.2) × 10–9 −1 s−1 Pa−1. FTIR analysis revealed strong component interactions. The composite films demonstrated biodegradability in compost after seven days and effective action against Listeria innocua and Saccharomyces cerevisiae. These findings suggest that these materials hold promise as active films for food preservation.
Ácidos grasos omega-3 y enfermedad cardiovascular
Ácidos grasos omega-3 y enfermedad cardiovascular; Omega-3 fatty acids and cardiovascular disease
Zago, Valeria
El interés en los posibles beneficios cardiovasculares de los ácidos grasos poliinsaturados omega-3 (AG n-3) no es nuevo, comenzó en la década de 19401,2 y se amplificó con un ensayo histórico posterior que mostró una reducción del riesgo de enfermedad cardiovascular (ECV) después de un infarto agudo de miocardio.3 Sin embargo, desde entonces ha circulado mucha controversia debido a resultados discordantes entre varios estudios, e incluso metanálisis, lo que hace que se sigan estudiando para tratar de entender mejor los mecanismos por los cuales podrían tener o no esos efectos sobre la ECV.
Fishing Vessel Bulbous Bow Hydrodynamics—A Numerical Reverse Design Approach
Fishing Vessel Bulbous Bow Hydrodynamics—A Numerical Reverse Design Approach
Díaz Ojeda, Héctor Rubén; Oyuela, Sebastian; Sosa, Roberto; Otero, Alejandro Daniel; Pérez Arribas, Francisco
Naval hydrodynamics typically focus on reducing ship resistance, which can be achieved by incorporating a bulbous bow. This feature is commonly used in the merchant fleet and smaller vessels, such as fishing boats, to minimize wave-making resistance. However, it is important to note that the use of a bulbous bow may not always be necessary or effective in all ship designs. In some cases, fishing ship designs may include a bulbous bow that is not optimized due to the use of procedures and methods intended for larger merchant ships or based on past experience. This study examines the effect of different bow designs, including the bulbous bow, on ship resistance in calm water, with a focus on a typical Argentinian trawler fishing vessel. The objective of this research is to assess the hydrodynamics of various designs for a particular ship by modifying its vessel lines. Firstly, the bulbous bow is removed, and then the reduction in ship resistance achieved by the bulbous bow under different load conditions and speeds is evaluated by comparing the vessel with and without the bulbous bow. The numerical analysis is performed using OpenFOAM, and the results are validated through towing tank experiments. This research indicates that the performance of the bulbous bow varies under different conditions. Therefore, it is recommended to conduct an initial study and a full evaluation of the design and operation alternatives.
La territorialidad en el enfoque de los distritos industriales: Una revisión teórica-metodológica desde la periferia
La territorialidad en el enfoque de los distritos industriales: Una revisión teórica-metodológica desde la periferia; Territoriality in the Industrial District’s Approach: A Theoretical-Methodological Review from the Periphery; Territorialidade na abordagem dos distritos industriais: Uma revisão teórico-metodológica da periferia
Trucco, Ignacio Tomas
Las investigaciones sobre la naturaleza y el rol de la territorialidad en los sistemas industriales locales se intensificaron desde fines de la década de 1960 cuando fue recuperada la noción marshalliana de “distrito industrial” (DI), que la introdujo como una doble realidad, geográfica y cultural, con un papel tan decisivo como difícil de definir. En este marco el trabajo se propone, por un lado, analizar la evolución de la territorialidad como dimensión inherente a los DI. Se desarrolla su metamorfosis conceptual a partir de las dificultades que emergieron en su articulación con las relaciones capitalistas de producción. Por otro lado, el trabajo busca contribuir a una reelaboración de esta cuestión a partir de los DI en espacios periféricos. Se intenta mostrar cómo, en la especificidad de la periferia, el DI debió abrirse a la influencia de relaciones extra locales, exponiendo la necesidad de una redefinición de la territorialidad en tanto relación social productora de múltiples escalas, articuladas con el despliegue a-espacial de las relaciones capitalistas de producción. La noción de DI es reelaborada en dicho contexto como una formación socio económica específica y cualitativamente diferente, relativa al proceso de acumulación y su articulación escalar.; Research on the nature and role of territoriality in local industrial systems has intensified since the late 1960s when the Marshallian notion of industrial district (id) was recovered, which introduced it as a double reality, geographical and cultural, with a role as decisive as it is difficult to define. Within this framework, the paper proposes, on the one hand, to analyze the evolution of territoriality as a dimension inherent to id. It develops its conceptual metamorphosis from the difficulties that emerged in its articulation with the capitalist relations of production. On the other hand, we seek to contribute to a rework of this issue based on id in peripheral spaces. We try to show how, in the specificity of the periphery, the id had to open itself to the influence of extra-local relations and it exposed the need for a redefinition of territoriality as a social relation producer of multiple scales, articulated with the a-spatial deployment of capitalist relations of production. The notion of id is reworked in this context as a specific and qualitatively different socioeconomic formation, related to the accumulation process and its scalar articulation.; A pesquisa sobre a natureza e o papel da territorialidade nos sistemas industriais locais tem se intensificado desde o final da década de 1960, quando a noção marshalliana de distrito industrial (di) foi revivida, o que a introduziu como uma realidade dupla, geográfica e cultural, com um papel tão decisivo quanto difícil de definir. Dentro dessa estrutura, no artigo se propõe, por um lado, analisar a evolução da territorialidade como uma dimensão inerente aos di. Sua metamorfose conceitual é desenvolvida com base nas dificuldades que surgiram em sua articulação com as relações de produção capitalistas. Por outro lado, no artigo procura-se contribuir para uma reelaboração dessa questão com base nas identidades em espaços periféricos. Procura-se mostrar como, na especificidade da periferia, o di teve que se abrir à influência de relações extralocais, e expôs a necessidade de uma redefinição da territorialidade como uma relação social que produz múltiplas escalas, articuladas com a implantação a-espacial das relações de produção capitalistas. A noção de di é reelaborada nesse contexto como uma formação socioeconômica específica e qualitativamente diferente, relacionada ao processo de acumulação e sua articulação escalar.
Taxogenomic analyses of Starmerella gilliamiae f.a, sp. nov. and Starmerella monicapupoae f.a., sp. nov., two novel species isolated from plant substrates and insects
Taxogenomic analyses of Starmerella gilliamiae f.a, sp. nov. and Starmerella monicapupoae f.a., sp. nov., two novel species isolated from plant substrates and insects
Rosa, Carlos Augusto; Santos, Ana Raquel O.; Palmier, Kirsten; Duell, Meghan; Carvalho, Andrea O. S.; Fernández, Natalia Verónica; Pimenta, Raphael S.; Morais, Paula B.; Araya, Macarena; Cubillos, Francisco A.; Pontes, Ana; Aires, Andreia; Gonçalves, Carla; Gonçalves, Paula; Sampaio, José Paulo; Lachance, Marc André
Four yeast isolates collected from flowers from different ecosystems in Brazil, one from fruit of Nothofagus alpina in Argentina, three from flowers of Neltuma chilensis in Chile and one obtained from the proventriculus of a female bumblebee in Canada were demonstred, by analysis of the sequences of the internal transcribed spacer (ITS) region and D1/D2 domains of the large subunit rRNA gene, to represent two novel species of the genus Starmerella. These species are described here as Starmerella gilliamiae f.a, sp. nov. (CBS 16166T; Mycobank MB 851206) and Starmerella monicapupoae f.a., sp. nov. (PYCC 8997T; Mycobank MB 851207). The results of a phylogenomic analysis using 1037 single-copy orthogroups indicated that S. gilliamiae is a member of a subclade that contains Starmerella opuntiae, Starmerella aceti and Starmerella apicola. The results also indicated that S. monicapupoae is phylogenetically related to Starmerella riodocensis. The two isolates of S. monicapupoae were obtained from flowers in Brazil and were probably vectored by insects that visit these substrates. Starmerella gilliamiae has a wide geographical distribution having been isolated in flowers from Brazil and Chile, fruit from Argentina and a bumblebee from Canada.
Role of hydroxymethylglutharyl-coenzyme A reductase in the induction of stem-like states in breast cancer
Role of hydroxymethylglutharyl-coenzyme A reductase in the induction of stem-like states in breast cancer
Marks, Maria Paula; Giménez, Carla Alejandra; Isaja, Luciana; Vera, Mariana Belén; Borzone, Francisco Raúl; Pereyra Bonnet, Federico Alberto; Romorini, Leonardo; Videla Richardson, Guillermo; Chasseing, Norma Alejandra; Calvo, Juan Carlos; Vellón, Luciano
Purpose: De novo synthesis of cholesterol and its rate-limiting enzyme, hydroxymethylglutharyl-coenzyme A reductase (HMGCR), is deregulated in tumors and critical for tumor cell survival and proliferation. However, the role of HMGCR in the induction and maintenance of stem-like states in tumors remains unclear. Methods: A compiled public database from breast cancer (BC) patients was analyzed with the web application SurvExpress. The web application Cell Miner was used for the analysis of HMGCR expression and statin sensitivity of the NCI-60 cell lines panel. A CRISPR-on system was used to induce HMGCR overexpression in the luminal BC cell line MCF-7 and a lentiviral pLM-OSKM system for the reprogramming of MCF-7 cells. Comparisons were performed by two-tailed unpaired t-test for two groups and one- or two-way ANOVA. Results: Data from BC patients showed that high expression of several members of the mevalonate pathway were associated with lower recurrence-free survival, particularly in hormone-receptor-positive BC. Cell Miner showed that HMGCR is expressed in several BC cancer cell lines, data validated by qRT-PCR in a BC cell lines panel. BC cells showed a subtype-dependent response to statins in silico and in vitro, partially determined by HMGCR. A stem-like phenotype was demonstrated upon HMGCR expression in MCF-7 cells, characterized by expression of the pluripotency markers NANOG, SOX2, increased CD44+/CD24low/-, CD133+ populations and increased mammosphere formation. Pluripotent and cancer stem cell lines showed high expression of HMGCR whereas cell reprogramming of MCF-7 cells did not increase HMGCR expression. Conclusion: HMCGR is associated with lower recurrence-free survival in BC and with stablished stem states.
Hybrid optimization model with Neural Network approach for renewable energy prediction and scheduling in large scale systems
Hybrid optimization model with Neural Network approach for renewable energy prediction and scheduling in large scale systems
Alvarez, Gonzalo Exequiel
Climate change demands clean energy solutions, and renewable sources such as solar and wind are prime candidates. However, their variability poses challenges for their integration into large-scale power systems. This paper addresses this issue by proposing a novel hybrid mathematical model. The proposal integrates both fossil and renewable sources, considering real-world constraints such as system demand, reserves, and transmission dynamics. The model combines several approaches. By using a novel block composition technique, the computational complexity is reduced, making the model applicable to large-scale systems. A neural network is also developed to improve the forecasting of renewable energy production, which is crucial for managing its intermittency. The effectiveness of the proposed model is tested by considering the large Argentinean electricity system, demonstrating its practical applicability. The results show that acceptable forecasts can be obtained for the generation and transmission scheduling of the whole system.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Westerlund 1 and 2 Open Clusters Survey
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Westerlund 1 and 2 Open Clusters Survey
Guarcello, Mario Giuseppe; Flaccomio, Ettore; Albacete Colombo, Juan Facundo; Almendros Abad, Víctor; Anastasopoulou, Konstantina; Andersen, M.; Argiroffi, C.; Bayo, Amelia; Bartlett, E.S.; Bastian, N.; De Becker, Michaël; Best, William M. J.; Bonito, R.; Borghese, Alice; Calzetti, D.; Castellanos, R.; Cecchi Pestellini, C.; Clark, J. S.; Clarke, C. J.; Zelati, Francesco Coti; Damiani, Jeremy; Drake, J.J.; Gennaro, Mario; Mapelli, M.; Martinez Galarza, J. R.; Micela, G.; Miceli, M.; Moraux, E.; Winter, A.; Wright, N. J.; Zeidler, Peter
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions among stars. Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars. The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun. Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically, the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec. Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation were carried out using the ACIS-Extract software. Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a photon flux threshold of approximately 2 × 10−8 photons cm−2 s −1 . The X-ray sources exhibit a highly concentrated spatial distribution, with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Fire Alarm!
Fire Alarm!
Gago, Maria Veronica
Short Takes: Provocations on Public Feminism, an open-access feature of Signs: Journal of Women in Culture and Society, offers brief comments from prominent feminists about a book that has shaped popular conversations about feminist issues. Short Takes is part of the Feminist Public Intellectuals Project.
Genome sequencing and analysis of black flounder (Paralichthys orbignyanus) reveals new insights into Pleuronectiformes genomic size and structure
Genome sequencing and analysis of black flounder (Paralichthys orbignyanus) reveals new insights into Pleuronectiformes genomic size and structure
Villarreal, Fernando Daniel; Burguener, Germán Federico; Sosa, Ezequiel Omar; Stocchi, Nicolas; Somoza, Gustavo Manuel; Turjanski, Adrian; Blanco, Andres; Viñas de Puig, Jordi; Mechaly, Alejandro
Black flounder (Paralichthys orbignyanus, Pleuronectiformes) is a commercially significant marine fish with promising aquaculture potential in Argentina. Despite extensive studies on Black flounder aquaculture, its limited genetic information available hampers the crucial role genetics plays in the development of this activity.In this study, we first employed Illumina sequencing technology to sequence the entire genome of Black flounder. Utilizing two independent libraries—one from a female and another from a male—with 150 bp paired-end reads, a mean insert length of 350 bp, and over 35 X-fold coverage, we achieved assemblies resulting in a genome size of ~538 Mbp. Analysis of the assemblies revealed that more than 98% of the core genes were present, with more than 78% of them having more than 50% coverage.This indicates a somehow complete and accurate genome at the coding sequence level. This genome contains 25,231 protein-coding genes, 445 tRNAs, 3 rRNAs, and more than 1,500 non-coding RNAs of other types. Black flounder, along with pufferfishes, seahorses, pipefishes, and anabantid fish, displays a smaller genome compared to most other teleost groups. In vertebrates, the number of transposable elements (TEs) is often correlated with genome size. However, it remains unclear whether the sizes of introns and exons also play a role in determining genome size. Hence, to elucidate the potential factors contributing to this reduced genome size, we conducted a comparative genomic analysis between Black flounder and other teleost orders to determine if the small genomic size could be explained by repetitive elements or gene features, including the whole genome genes and introns sizes. We show that the smaller genome size of flounders can be attributed to several factors, including changes in the number of repetitive elements, and decreased gene size, particularly due to lower amount of very large and small introns. Thus, these components appear to be involved in the genome reduction in Black flounder. Despite these insights, the full implications and potential benefits of genome reduction in Black flounder for reproduction and aquaculture remain incompletely understood, necessitating further research.
Una aproximación a la apicultura en clave de género
Una aproximación a la apicultura en clave de género; An approach to beekeeping in a gender key
Vázquez, Jimena Soledad; Vázquez, Javier Carlos
La apicultura es una actividad con un valor sociocultural, económico y ecológico. En Argentina, el principal producto de la colmena es la miel. La investigación marco pretende la elaboración de un diagnóstico con perspectiva de género sobre la actividad. La complejidad del fenómeno demanda una triangulación de datos cualitativos y cuantitativos. Aquí presentamos los segundos, recabados a través de dos cuestionarios durante cinco meses de trabajo de campo realizado durante el año 2023. Entre los principales resultados podemos mencionar que la apicultura aparece como una actividad masculinizada, aunque hay una participación de mujeres predominantemente en tareas de producción y venta de productos. Es una actividad considerada como vocacional y familiar, manejada en general por dos personas y con bajos niveles de registro sobre la productividad. La mayoría de los/as productores/as no participa de cooperativas apícolas, ni posee salas de extracción de miel propias.; Beekeeping is an activity with sociocultural, economic and ecological value. In Argentina, the main product of the hive is honey. The framework research aims to develop a diagnosis with a gender perspective on the activity. The complexity of the phenomenon demands a triangulation of qualitative and quantitative data. Here we present the latter, collected through two questionnaires during five months of field work carried out during the year 2023. Among the main results we can mention that beekeeping appears as a masculinized activity, although there is predominantly female participation in production tasks. and product sales. It is an activity considered vocational and family, generally managed by two people with low levels of productivity records. The majority of producers do not participate in beekeeping cooperatives, nor do they have their own honey extraction rooms.
Planet formation around intermediate-mass stars. I: different disc evolutionary pathways as a function of stellar mass
Planet formation around intermediate-mass stars. I: different disc evolutionary pathways as a function of stellar mass
Ronco, María Paula; Schreiber, Matthias R.; Villaver, E.; Guilera, Octavio Miguel; Miller Bertolami, Marcelo Miguel
Context. The study of protoplanetary disc evolution and theories of planet formation has predominantly concentrated on solar- (andlow-) mass stars since they host the majority of confirmed exoplanets. Nevertheless, the confirmation of numerous planets orbitingstars more massive than the Sun (up to ∼3 M⊙) has sparked considerable interest in understanding the mechanisms involved in theirformation, and thus in the evolution of their hosting protoplanetary discs.Aims. We aim to improve our knowledge of the evolution of the gaseous component of protoplanetary discs around intermediate-massstars and to set the stage for future studies of planet formation around them.Methods. We study the long-term evolution of protoplanetary discs affected by viscous accretion and photoevaporation by X-ray andfar-ultraviolet (FUV) photons from the central star around stars in the range of 1–3 M⊙, considering the effects of stellar evolution andsolving the vertical structure equations of the disc. We explore the effect of different values of the viscosity parameter and the initialmass of the disc.Results. We find that the evolutionary pathway of protoplanetary disc dispersal due to photoevaporation depends on the stellar mass.Our simulations reveal four distinct evolutionary pathways for the gas component not reported before that are a consequence of stellarevolution and that likely have a substantial impact on the dust evolution, and thus on planet formation. As the stellar mass increasesfrom one solar mass to ∼1.5–2 M⊙, the evolution of the disc changes from the conventional inside-out clearing, in which X-ray photoevaporation generates inner holes, to a homogeneous disc evolution scenario where both inner and outer discs formed after a gap isopened by photoevaporation vanish over a similar timescale. As the stellar mass continues to increase, reaching ∼2–3 M⊙, we identifya distinct pathway that we refer to as revenant disc evolution. In this scenario, the inner and outer discs reconnect after the gap opened.For the largest masses, we observe outside-in disc dispersal, in which the outer disc dissipates first due to a stronger FUV photoevaporation rate. Revenant disc evolution stands out as it is capable of extending the disc lifespan. Otherwise, the disc dispersal timescaledecreases with increasing stellar mass except for low-viscosity discs
Uso de pantallas y su influencia en la cognición y los hitos del desarrollo motor de infantes mexicanos
Uso de pantallas y su influencia en la cognición y los hitos del desarrollo motor de infantes mexicanos; Use of screens and their influence on cognition and motor development milestones in Mexican infants
Robles Estrada, Erika; del Carpio Ovando, Perla S.; Gago Galvagno, Lucas Gustavo
El uso de pantallas está presente a temprana edad. Aunque hay evidencia de los efectos negativos del uso de dispositivos digitales en el desarrollo cognitivo de los niños, su estudio aún es un área emergente en países como México. El objetivo de este artículo fue describir y asociar el uso de pantallas con el lenguaje y los hitos del desarrollo de infantes mexicanos. Participaron 91 cuidadores primarios de infantes entre 12 y 36 meses, de diferentes regiones de México (Medad = 24.14 meses, DE = 8.26, mujer = 39.56%, hombre = 60.44%). Los instrumentos aplicados fueron la Encuesta Permanente de Hogares, Historia Clínica, Cuestionario del Uso de Libros y Pantallas Digitales, Cuestionario de Hitos del Desarrollo e Inventario de Desarrollo Comunicativo II. Los resultados indican que los infantes usan pantallas digitales entre 3 y 4 horas por día. La televisión es la más utilizada, así como el tiempo de uso que se comparte con algún adulto. A medida que aumenta el número de horas frente a las pantallas, la densidad léxica y uso de oraciones es menor. A medida que aumenta el uso de pantallas en el hogar, la adquisición de los hitos del desarrollo motor y del lenguaje es más tardía. Además, cuanto más acompaña un adulto al infante durante el uso de pantallas, hay mayores puntajes en los reportes de densidad léxica y uso de oraciones. Por último, se encontraron modelos generales estadísticamente significativos entre las variables dependientes, que fueron la densidad léxica que explicó el 28.9% de la variabilidad y los hitos del desarrollo motor, explicando el 16.7%. Las variables independientes fueron edad del niño, tiempo de uso y uso compartido. Sin embargo, sólo el uso compartido de pantallas predijo una adquisiciónmás temprana de los hitos del desarrollo motor. Se concluye que el uso de pantallas contribuiría de forma negativa al desarrollo temprano, aunque si hay un adulto acompañando su uso podría generar contribuciones positivas, lo que refuerza los estudios previos y las recomendaciones de aminorar su uso en los primeros años de vida.; The use of screens is present at a young age, however, it is documented that it has negative effects on the cognitive development of infants, although its study is still an emerging area in countries like Mexico, in such a way that the objective of this article was to describe and associate the use of screens with language and developmental milestones of Mexican infants. 91 primary caregivers of infants between 12 and 36 months, from different regions of Mexico participated (Mage = 24.14 months, SD = 8.26, female = 39.56%, male = 60.44%). The instruments applied were the Permanent Household Survey, Clinical History, Questionnaire on the Use of Books and Digital Screens, Questionnaire of Development Milestones and Inventory of Communicative Development II. The results indicate that infants use digital screens between 3 and 4 hours per day, television is the most used, as well as the time of use that is shared with an adult. As the number of hours in front of the screens increases, the lexical density and use of sentences is lower. As the use of screens in the home increases, the acquisition of developmental motor and language milestones is later. When an adult accompanies the infant, there is a higher use of lexical density, and the use of sentences is greater. Finally, general statistically significant models were found between the dependent variables, which were lexical density, which explained 28.9% of the variability, and motor development milestones, explaining 16.7%. The independent variables were child’s age, time of use, and shared use. However, only screen sharing predicted earlier acquisition of motor developmental milestones. It is concluded that the use of screens would contribute negatively to early development, although if there is an adult accompanying their use it could generate positive contributions, which reinforces previous studies and the recommendations to reduce their use in the first years of life.
Acciones e imágenes sobre la pobreza urbana en Buenos Aires y Seattle
Acciones e imágenes sobre la pobreza urbana en Buenos Aires y Seattle; Actions and images on urban poverty in Buenos Aires and Seattle
Canevaro, Santiago; Viotti, Nicolas; Elwood Faustino, Sarah
En el presente artículo analizamos la construcción relacional de la clase media en relación con la pobreza a partir de un trabajo comparativo entre Seattle y Buenos Aires durante el período de recuperación relativa de la crisis socioeconómica de la primera década del milenio. Con la teoría de la pobreza relacional como eje conceptual, entendemos que se reproducen o se desafían subjetividades de clase mediante interacciones que atraviesan o confrontan los límites entre grupos sociales. Y, también, que las relaciones con la pobreza pueden producir lecturas alternativas de la formación de la clase media en Estados Unidos y Argentina.; In this article we analyze the relational construction of the middle class from a comparative study between Seattle and Buenos Aires during the period of relative recovery of the socioeconomic crisis. With the theory of relational poverty as a conceptual axis, we understand that class subjectivities are reproduced or challenged through interactions that cross or confront the boundaries between social groups. Our analysis reveals that poverty is a key point for the formation of middle-class groups in both countries and that poverty can produce alternative readings of the formation of the middle class in the United States and Argentina.
Múltiples caminos a la tesina
Múltiples caminos a la tesina; Multiple Paths to the Thesis
Camou, Antonio; Benitez Larghi, Hector Sebastian; Pinedo, Jerónimo; Di Piero, María Emilia; González Canosa, Mora; Balerdi, Soledad; Busso, Mariana
El presente artículo reúne parte de los intercambios que tuvieron lugar en agosto de 2023 en ocasión de la segunda edición de la “Jornadas de tesinas del Departamento de Sociología”, en donde docentes, graduades y estudiantes de la carrera reflexionaron sobre las características de la tesina y las distintas formas de realizarla. El conversatorio titulado “Múltiples caminos a la tesina” fue moderado por Antonio Camou y participaron en calidad de expositoras/es (en orden alfabético): Emilia Di Piero, Jerónimo Pinedo, Mariana Busso, Mora González Canosa, Rodolfo Iuliano, Sebastián Benítez Larghi y Soledad Balerdi.; This paper brings together part of the conversations maintained during August 2023 in the second “Jornada de tesinas del Departamento de Sociología”. The professionals of the Department reflected on the writing of the thesis. It was moderated by Antonio Camou and Emilia Di Piero, Jerónimo Pinedo, Mariana Busso, Mora González Canosa, Rodolfo Iuliano, Sebastián Benítez Larghi and Soledad Balerdi participated.
Greedy-like bases for sequences with gaps
Greedy-like bases for sequences with gaps
Berasategui, Miguel Hernán; Berná, Pablo M.
In 2018, Oikhberg introduced and studied variants of the greedy and weak greedy algorithms for sequences with gaps, with a focus on the n-t-quasi-greedy property that is based on them. Building upon this foundation, our current work aims to further investigate these algorithms and bases while introducing new ideas for two primary purposes. First, we aim to prove that for n with bounded quotient gaps, n-t-quasi-greedy bases are quasi-greedy bases. This generalization extends a previous result to the context of Markushevich bases and, also, completes the answer to a question by Oikhberg. The second objective is to extend certain approximation properties of the greedy algorithm to the context of sequences with gaps and study if there is a relationship between this new extension and the usual convergence.
Concomitant Therapy of Inactivated Enterococcus faecalis CECT7121 with Fluoroquinolones in a Salmonella Enteritidis Murine Sepsis Model
Concomitant Therapy of Inactivated Enterococcus faecalis CECT7121 with Fluoroquinolones in a Salmonella Enteritidis Murine Sepsis Model
Schofs, Laureano; Sparo, Mónica Delfina; García Allende, Natalia; de Yaniz, María Guadalupe; Confalonieri, Alejandra; Sanchez Bruni, Sergio Fabian
AbstractOptimization of existing antimicrobial therapies is a strategy proposed for extending antimicrobial activity and delaying resistance development. This study aimed to assess the effect of inactivated E. faecalis CECT7121 (I-EFCECT7121) in a combined therapy with Enrofloxacin or Ciprofloxacin in a S. Enteritidis murine sepsis model. Firstly, dose titration studies were performed to set up: (a) Salmonella Enteritidis (SE) Lethal dose 99 (LD99) and (b) safety of I-EFCECT7121 (c) I-EFCECT7121 dosage scheme. Then, I-EFCECT7121 in combined therapy with 4 doses (5 mg/kg) per 12 h of CFX and EFX in an LD99 BALB/c infection, were evaluated. Survival rate was monitored for 20 days in order to estimate the treatment success. The efficacy of both drugs was improved by combining them with the inactivated bacteria. However, only a significant increase (p < 0.05) was observed after I-EFCECT7121 and CFX combined treatment (40% of survival rate). By contrast, each drug alone achieved a 10% of survival rate. These outcomes showed a potential therapeutic synergism when I-EFCECT7121 was concomitantly given with ciprofloxacin.
Thermal limits along tropical elevational gradients: Poison frog tadpoles show plasticity but maintain divergence across elevation
Thermal limits along tropical elevational gradients: Poison frog tadpoles show plasticity but maintain divergence across elevation
Paez Vacas, Monica Isabel; Funk, W. Chris
Temperature is arguably one of the most critical environmental factors impacting organisms at molecular, organismal, and ecological levels. Temperature variation across elevation may cause divergent selection in physiological critical thermal limits (CTMAX and CTMIN). Generally, high elevation populations are predicted to withstand lower environmental temperatures than low elevation populations. Organisms can also exhibit phenotypic plasticity when temperature varies, although theory and empirical evidence suggest that tropical ectotherms have relatively limited ability to acclimate. To study the effect of temperature variation along elevational transects on thermal limits, we measured CTMAX and CTMIN of 934 tadpoles of a poison frog species, Epipedobates anthonyi, along two elevational gradients (200–1700 m asl) in southwestern Ecuador to investigate their thermal tolerance across elevation. We also tested if tadpoles could plastically shift their critical thermal limits in response to exposure to different temperatures representing the range of temperatures they experience in nature (20 °C, 24 °C, and 28 °C). Overall, we found that CTMAX did not change across elevation. In contrast, CTMIN was lower at higher elevations, suggesting that elevational variation in temperature influences this thermal trait. Moreover, all populations shifted their CTMAX and CTMIN according to treatment temperatures, demonstrating an acclimation response. Overall, trends in CTMIN among high, mid, and low elevation populations were maintained despite plastic responses to treatment temperature. These results demonstrate that, for tadpoles of E. anthonyi across tropical elevational gradients, temperature acts as a selective force for CTMIN, even when populations show acclimation abilities in both, CTMAX and CTMIN. Our findings advance our understanding on how environmental variation affects organisms’ evolutionary trajectories and their abilities to persist in a changing climate in a tropical biodiversity hotspot.
Semiclosed multivalued projections
Semiclosed multivalued projections
Arias, Maria Laura; Contino, Maximiliano; Maestripieri, Alejandra Laura; Marcantognini Palacios, Stefania Alma María
A multivalued projection is an idempotent linear relation with invariant domain. We characterize multivalued projections that are operator ranges (called semiclosed) and provide several formulae of them. Moreover, we study the decomposability and continuity of multivalued projections, and describe nilpotent relations.
Páginas
