Metodologías para la detección de SARS-CoV-2 y análisis de carga viral mediante RT-PCR cuantitativa Jaquenod de Giusti, Carolina; Montanaro, Mauro Aldo; Mencucci, María Victoria; Canzoneri, Romina; Orlowski, Alejandro; Santana, Marianela; Pereyra, Erica Vanesa; Kraemer, Mauricio Nestor; Lavarias, Sabrina Maria Luisa; Moscoso, Verónica Victoria; Costantini, Noelia; Francini, Flavio; Garda, Horacio Alberto; Pedríni, Nicolás; Baro, María González; Petroff, Martín Vila; Aiello, Ernesto Alejandro; Abba, Martín Carlos En diciembre de 2019, se produjo un nuevo brote de enfermedad por coronavirus (COVID-19) en Wuhan, China. El síndrome respiratorio agudo severo-coronavirus-2 (SARS-CoV-2), que es el séptimo coronavirus conocido que infecta a los humanos, es altamente infeccioso y se ha expandido rápidamente en todo el mundo desde su descubrimiento. El diagnóstico de la infección por SARS-CoV-2 se basa en la detección del genoma viral (ARN) a través de técnicas de biología molecular. Con este fin, se extrae el ARN total para su posterior detección mediante PCR cuantitativa en tiempo real (RT-qPCR). Las pruebas cuantitativas de ácidos nucleicos se han convertido en el “estándar de oro” para el diagnóstico y guía en la toma de decisiones clínicas. Sin embargo, los ensayos de RT-qPCR dirigidos al SARS-CoV-2 tienen varios desafíos, especialmente en términos de diseño de cebadores / sondas y de desarrollo de metodologías que permitan estimar la carga viral en pacientes con diagnóstico de COVID-19.; In December 2019, a new coronavirus disease (COVID-19) outbreak occurred in Wuhan, China. Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), which is the seventh coronavirus known to infect humans, is highly contagious and has rapidly expanded worldwide since its discovery. Quantitative nucleic acid testing has become the gold standard for diagnosis and guiding clinical decisions regarding the use of antiviral therapy. Total RNA is purified for subsequent SARS-CoV-2 detection by a real time quantitative RT-PCR (RT-qPCR). However, the RTqPCR assays targeting SARS-CoV-2 have a number of challenges, especially in terms of primer / probe design and in the development of methodologies to estimate viral load in patients diagnosed with COVID-19.

Dynamics of feeding and defecation behavior of Triatoma infestans hybrids Lopez, Ana Graciela; Cardozo, Miriam; Oscherov, Elena Beatriz; Crocco, Liliana Beatriz Triatoma platensis is occasionally found coexisting with Triatoma infestans in chicken coops in Argentina. Some authors have reported the presence of hybrid specimens of both species in chicken coops and other peridomestic habitats. Given the coexistence of T. infestans with T. platensis and the possibility of generating fertile hybrids, it is important to evaluate the vectorial competence of these hybrids. The objective of this study was to record the dynamics of feeding-defecation behavior in fifth-stage nymphs and adults of hybrids between both species and to compare it with T. platensis and T. infestans. Three experimental groups were formed separated by stage and sex: Hybrid group, T. infestans group, and T. platensis group. During feeding, the following variables were recorded for each group: (i) blood meal size, (ii) feeding time, (iii) number of defecations during feeding, and (iv) number of defecations at 10 and 30 min after feeding. The results indicate that adults and fifth-instar nymphs of hybrids have a feeding and defecation behavior similar to T. infestans: they achieve feeding in a short time and first defecation occurs during or just after feeding. Nevertheless, hybrid’s ingestion of blood occurs at higher velocity and they require higher blood intake to provoke early defecations. Considering the blood ingestion velocity, the amount of blood ingested, and the short time required for the production of the first defecation, the results of this study suggest that hybrid can be a competent Trypanosoma cruzi vector.

Pandemia y virtualidad forzada en la escuela para adultos. Reflexiones, aportes y experiencias educativas desde el C.E.N.S Nº 1; Pandemic and forced virtuality in adult school. Reflections, contributions and educational experiences from C.E.N.S No. 1 Ibañez, Cecilia Elizabeth; Hernandez, Maria Eugenia Como consecuencia de la intempestiva suspensión de la educación presencial, acaecida en el marco de las medidas de aislamiento social preventivo y obligatorio dispuestas para contener la propagación de la enfermedad viral, se desplegaron diversas estrategias para dar continuidad a la educación formal, adquiriendo, preeminencia, dentro de ellas, la modalidad virtual de enseñanza. Considerando ello, nos proponemos caracterizar el desarrollo de la continuidad educativa a partir del establecimiento del nuevo modo de trabajo virtual en las escuelas C.E.N.S Nº 1 de Santiago del Estero, teniendo en cuenta los singulares condicionamientos sociales y económicos que atraviesan los estudiantes de estas instituciones. Para abordar este objetivo, además del recorrido por el desarrollo teórico conceptual pertinente se trabaja con material empírico recabado mediante el trabajo de campo consistente en encuestas a alumnos y docentes y entrevistas a las autoridades de la referida escuela C.E.N.S. El estudio permite advertir que la modalidad virtual opera como un condicionamiento más para este grupo de alumnos, manifestado en la escasa participación de los estudiantes.; As a consequence of the abrupt suspension of face-to-face education, which occurred within the context of the “preventive and compulsory social isolation [PCSI]” measures decided to contain the spread of the viral disease, various strategies were deployed to give continuity to formal education, acquiring preeminence, within them, the virtual teaching modality. Considering this, we propose to characterize the development of educational continuity from the establishment of the new form of virtual education in schools C.E.N.S No. 1 of Santiago del Estero, taking into account the unique social and economic conditions that defines the students of these institutions. To address this objective, in addition to the exploration of the relevant conceptual theoretical development, we analyze an empirical material collected through field work consisting of students and teachers surveys and interviews with the authorities of the referred school C.E.N.S. The study allows us to know that the virtual modality operates as one more conditioning for this group of students, manifested in the low participation of students.

El género Pannaria (Pannariaceae) en la Argentina: Nuevos registros y actualización del conocimiento Passo, Alfredo; Díaz Dominguez, Raúl Enrique; Rodriguez, Juan Manuel Introducción & Objetivos: Como parte de estudios a largo plazo enfocados en la diversidad de hongos liquenizados en la Argentina, se presenta una revisión sobre el género Pannaria para el país. Este género nunca ha sido estudiado en detalle en nuestro territorio. M&M: La morfología, anatomía y química de las especies fue estudiada por medio de la revisión de ejemplares frescos recolectados en el campo y el estudio de diferentes colecciones de herbario, siguiendo protocolos estandarizados. Resultados: Se registraron 15 especies de Pannaria, 3 de ellas por primera vez para la Argentina: P. conoplea, P. malmei y P. tavaresii. Se propone una nueva sinonimia (P. euphylla = P. calophylla). Se presentan descripciones, fotografías e información actualizada sobre la distribución y ecología de las especies, y una clave para su identificación. Conclusiones: La mayoría de las especies mencionadas se encuentran en los bosques andino-patagónicos, con la excepción de P. conoplea, P. malmei y P. tavaresii, que se encontraron en el centro de Argentina, en bosques de altura de Polylepis.; Background and aims: As part of long-term studies focused on the diversity of lichenized fungi in Argentina, a review of the genus Pannaria in the country is presented. This genus have never been studied in detail in our territory. M&M: The morphology, anatomy and chemistry of the species were studied through the review of fresh specimens collected in the field and the study of different herbarium collections, following standardized protocols. Results: Fifteen species of Pannaria are registered for Argentina, 3 of them for the first time: P. conoplea, P. malmei, and P. tavaresii. A new synonym is proposed (P. euphylla = P. calophylla). Descriptions, photographs, and actualized information on their distribution and ecology, and a key for their identification are presented. Conclusions: Most of the mentioned species were found in the Andean-Patagonian forests, with the exception of P. conoplea, P. malmei and P. tavaresii, which were found in central Argentina, in high altitude forests of Polylepis.

Stenting as porous media in anatomically accurate geometries: A comparison of models and spatial heterogeneity Dazeo, Nicolás Ignacio; Dottori, Javier Alejandro; Boroni, Gustavo Adolfo; Narata, Ana Paula; Larrabide, Ignacio Modelling intracranial aneurysm blood flow after flow diverter treatment has proven to be of great scientific and clinical interest. One of the reasons for not having CFD as an everyday clinical tool yet is the time required to set-up such simulations plus the required computational time. The speed-up of these simulations can have a considerable impact during treatment planning and device selection. Modelling flow diverters as a porous medium (PM) can considerably improve the computational time. Many models have been presented in literature, but quantitative comparisons between models are scarce.In this study, the untreated case, the explicit definition of the flow diverter wires as no-slip boundary condition and five different porous medium models were chosen for comparison, and evaluated on intracranial aneurysm of 14 patients with different shapes, sizes, and locations. CFD simulations were made using finite volume method on steady flow conditions. Velocities, kinetic energy, wall shear stress, and computational time were assessed for each model. Then, all models are compared against the no-slip boundary condition using non parametric Kolmogorov–Smirnov test.The model with least performance showed a mean K-S statistic of 0.31 and deviance of 0.2, while the model with best values always gave K-S statistics below 0.2. Kinetic energy between PM models varied between an over estimation of 218.3% and an under estimation of 73.06%. Also, speedups were between 4.75x and 5.3x (stdev: 0.38x and 0.15x) when using PM models.Flow diverters can be simulated with PM with a good agreement to standard CFD simulations were FD wires are represented with no-slip boundary condition in less than a quarter of the time. Best results were obtained on PM models based on geometrical properties, in particular, when using a heterogeneous medium based on equations for flat rhomboidal wire frames.

Ciudades medias: problematizando la escala Silva, Ana Cecilia Desde distintas perspectivas –epidemiológicas, políticas, urbanísticas, mediáticas- la cuestión de la escala urbana ha sido recurrentemente significada como una dimensión relevante para abordar, gestionar y/o experimentar de manera diferencial el alcance y el impacto de la propagación de la enfermedad causada por el coronavirus SARS-CoV-2. Este trabajo retoma algunos resultados de investigaciones previas sobre ciudades medias de la provincia de Buenos Aires desarrolladas en el marco del NACT PROINCOMSCI de la Facultad de Ciencias Sociales de la UNICEN, con el propósito de problematizar la cuestión de la escala urbana a la luz de los procesos implicados por las diferentes medidas de aislamiento y distanciamiento social implementadas para hacer frente a la pandemia de Covid-19. En particular, se propone abordar la medianidad como categoría analítica etnográficamente informada que permite indagar en la experiencia de la escala media para un abordaje relacional y situado de la efectivización de dichas medidas en la ciudad de Olavarría.

“La casa convertida en mundo” como contexto de aprendizaje en tiempos de pandemia Bengtsson, Astrid Mariana; Bugallo, Lucía; Coccoz, Verónica; D'Adamo, Paola; Lozada, Mariana; Méndez, Laura Marcela; Pedrazzini, Ana Mercedes; Pérez, Soledad Analía; Rapela, Verónica; Salsa, Analía Marcela; Scheuer, Nora; Tozzini, María Alma; Ventura, Ana Clara Vivir y convivir en casa mucho más tiempo que lo habitual plantea el desafío de cómo hacer confluirtiempos diversos, de construir nuevas formas de habitarla. En muchas familias, se trata de encontrarformas de conjugar el tiempo doméstico y el ocioso (con horarios y reglas que se negocian en la familia), junto con el del estudio (si las instituciones educativas proponen una agenda de trabajo) y, para quienes somos docentes, requiere apropiarse de nuevas formas de trabajo, estrategias, problemas y desafíos.

Fire reduces dry season low flows in a subtropical highland of central Argentina Cingolani, Ana María; Poca, María; Whitworth Hulse, Juan Ignacio; Giorgis, Melisa Adriana; Vaieretti, Maria Victoria; Herrero, María Lucrecia; Navarro Ramos, Silvia Elisa; Renison, Daniel Wildfires are recurrent in seasonally-dry ecosystems; however, their effects on streamflows at the end of the dry season (low flows) are not well understood. The infiltration-evapotranspiration trade-off hypothesis postulates that when vegetation cover is lost or degraded, low flows in the following dry season are reduced due to impaired water infiltration and storage in soils during the wet season, which surpass gains due to diminished evapotranspiration. We tested this hypothesis in the context of vegetation loss produced by fire. For this purpose, we seized a wildfire in a subtropical highland of central Argentina and selected 12 burnt and 12 unburnt catchments of 15–60 ha. We measured low flows at the outlet point of each catchment in two opportunities: one year after the fire (post-fire dry season) and in a dry season not affected by previous fire (control dry season). Using the 12 unburnt catchments, we built linear regression models to estimate the expected low flows for the post-fire dry season under a no-fire scenario. The predictor variables were low flows in the control dry season. We applied the models to burnt catchments and compared the expected with the observed low flows. We also evaluated vegetation activity through satellite images. Burnt catchments showed significant low flow reductions of 31–48% compared with expectations under a no-fire scenario, supporting the infiltration-evapotranspiration trade-off hypothesis. Vegetation activity was lower in burnt than in unburnt catchments only for the first three months after the fire, while it was more active since then for one year. Together our results suggest that post-fire reduced low flows can be explained by a reduced infiltration, as well as by higher evapotranspiration due to increased vegetation activity. Given the extent of seasonally dry ecosystems worldwide, we highlight the importance of controlling wildfires to improve streamflow in the dry-season.

Los efectos de la cuarentena por coronavirus (Covid-19) en los hábitos alimentarios en Argentina; Impact of the quarantine by coronaviruses (Covid-19) on food habits in Argentina Sudriá, María Emilce; Andreatta, María Marta; Defagó, María Daniela Introducción: debido a la pandemia del coronavirus humano COVID-19, se implementaron estrategias preventivas basadas en el aislamiento social preventivo y obligatorio (cuarentena) para reducir la transmisión en la comunidad, lo cual ha impactado en el estilo de vida y en los hábitos alimentarios.Objetivo: analizar el consumo alimentario durante el período de cuarentena en Argentina.Material y Método: se desarrolló un estudio observacional, exploratorio, de corte transversal. Se diseñaron dos cuestionarios de encuesta para ser completados en formato online, uno para la población que consume carnes (PC) y otro para la población veg(etari)ana (PV). Se incluyeron preguntas de opción múltiple sobre características sociodemográficas, peso y talla autoreferidos, antecedentes de enfermedades crónicas, ingesta habitual de alimentos y su percepción de modificación durante el período de aislamiento social. A 12 días de decretada la cuarentena, se hizo un primer corte en el relevamiento de datos para realizar un análisis descriptivo.Resultados: la muestra quedó conformada por 2518 personas que contestaron el formulario (2201 PC y 317 PV). Se observó una modificación en los hábitos alimentarios en el período de encierro en ambos grupos, caracterizada principalmente por un descenso en el consumo de alimentos con potencial inmunomodulador como frutas y verduras y un aumento en la ingesta de alimentos desaconsejados como panificados, golosinas, bebidas azucaradas y alcohólicas.Conclusiones: es fundamental considerar el impacto acontecido en el estilo de vida y específicamente en la alimentación, ya que dietas poco saludables podrían aumentar la susceptibilidad a COVID-19 y afectar la recuperación.

Heroínas feministas en la historieta: Género, memoria y disidencia sexual en Dora de Minaverry Saxe, Facundo Nazareno Este artículo aborda la emergencia de protagonistas / heroínas en la historieta argentina reciente, en particular el caso del cómic Dora de Ignacio Minaverry que cuenta hasta 2018 con tres tomos en circulación. Se analiza esta saga como parte de una conste-lación de apariciones de protagonistas mujeres sexo-disidentes en la historieta argentina reciente, diferente a la posición ocupada por personajes mujeres en épocas anteriores en la historieta. En ese sentido, el personaje de Dora podría apreciarse como parte de una producción de heroínas del siglo XXI en la historieta argentina. Éstas a diferencia de pro-tagonistas femeninas de otros períodos son parte constitutiva de una modalidad cercana a una perspectiva de sexo-género feminista para el desarrollo de los relatos visuales propios del cómic. Dora es un personaje que construye un camino diferente y en algún sentido inusual para la historieta argentina tradicional y heteropatriarcal, se trata de una heroína de tiempos feministas, sexo-disidente y cuya historieta aborda temas de género. En ese marco, el cómic cruza la reflexión de una perspectiva de sexo-género con la memoria y temáticas icónicas de la historieta como el cómic de espías o el abordaje del pasado trau-mático. Dora es parte de una generación que muestra otras posibilidades para el cómic argentino, por lo que su aparición podría implicar un cambio en el horizonte de los relatos historietísticos argentinos. Temas como el afecto por fuera de la heteronorma, la disiden-cia sexual, el aborto, la identidad, la amistad, el lugar de la mujer en la historia, entre otros, forman parte de las aventuras de Dora hasta el momento.; This paper deals with the emergence of protagonists / heroines in the recent ar-gentin comic, in particular the case of Dora, create by Ignacio Minaverry and that counts until 2018 with three volumes in circulation. In this paper, this saga will be analyzed as part of a constellation of protagonic appearances by sex-dissident women in the recent argentin comic, wich is different from the position occupied by female characters in other times in the comic. In that sense, the character of Dora could be seen as part of a production of heroines of the 21st century in the argentine comic industrie. Unlike female protagonists of the heterosexist male tradition, the Dora's comic is produced from a feminist sex-gender perspective. Dora is a character who constructs a different way for the traditional and het-eropatriarchal argentin comic, she is a heroine of feminist times and whose adventures deals with gender issues. In this context, the comic crosses the reflection of a sex-gender perspective with the memory and iconic themes of the comic strip, such as the spy comic or the approach to the traumatic past. Dora is part of a generation that shows other pos-sibilities for the argentine comic, so the appearance of characters like Dora could imply a change in the horizon of Argentine historical stories. Topics such as affection outside the heteronorm, sexual dissidence, abortion, identity, friendship, the place of women in his-tory, among others, are part of the adventures of Dora in these three volumes.; Este artigo trata do surgimento de protagonistas / heroínas no recente comic argentino, em particular o caso da história em quadrinhos Dora, feita por Ignacio Mina-verry e que conta até 2018 com três volumes em circulação. Neste artigo, essa saga será analisada como parte de uma constelação de aparições de mulheres protagonistas sexo--dissidentes no recente comic argentino, diferente da posição ocupada por personagens femininas em épocas anteriores nos quadrinhos. Nesse sentido, o caráter de Dora poderia ser visto como parte de uma produção de heroínas do século XXI no comic argentino. Es-tes, ao contrário de protagonistas femininos de outros períodos, são parte constitutiva de uma modalidade próxima a uma perspectiva feminista de sexo-gênero para o desenvolvi-mento das próprias histórias visuais da história em quadrinhos. Dora é uma personagem que constrói um desenho diferente e incomum para o comic tradicional e heteropatriarcal argentino, ela é uma heroína de tempos feministas, sexo-dissidente e cuja história em quadrinhos lida com questões de gênero. Nesse contexto, a obra cruza a reflexão de uma perspectiva de sexo-gênero com a memória e os temas icônicos da história em quadri-nhos, como o comic dos espiões ou a abordagem do passado traumático. Dora faz parte de uma geração que mostra outras possibilidades para o comic argentino, então a aparição de personagens como Dora poderia implicar uma mudança no horizonte das histórias em quadrinhos argentinas. Temas como afeto fora do heteronorma, dissidência sexual, aborto, identidade, amizade, o lugar da mulher na história, entre outros, fazem parte das aventuras de Dora nesses três volumes.

The petrogenesis of back-arc magmas, constrained by zircon O and Hf isotopes, in the Frontal Cordillera and Precordillera, Argentina Poole, Gregory H.; Kemp, Anthony I. S.; Hagemann, Steffen G.; Fiorentini, Marco L.; Jeon, Heejin; Williams, Ian S.; Zappettini, Eduardo Osvaldo; Rubinstein, Nora Alicia The Andean margin of the South American continent has been magmatically and tectonically active for over 330 million years. It is the type location where “Cordilleran-type” magmatism and orogenesis are manifest. In Argentina and Chile, between the latitudes of 28° and 40° S, magmatism related to the Gondwanan “Cordilleran-type” orogeny is reflected in a series of Carboniferous to Triassic intrusions. A comprehensive model exists for the petrogenesis of such magmas in Chile, however there is relatively little understanding of the nature and timing of Permo-Triassic magmatism in the Frontal Cordillera and Precordillera in Argentina. To address this, we present a new dataset of in situ zircon U–Pb, O and Hf isotopes from 15 felsic intrusions from Argentina. Zircon geochronology shows that magmatism in this region commenced at ca. 285 Ma and continued until ca. 250 Ma. Zircon O and Hf isotopes suggest that the oldest Permian magmas were derived from young supracrustal sources, with elevated δ18O (~ 8.5 to 7.5‰) and negative εHf values (~ − 1 to − 3 εHf). The emplacement of these magmas was coeval with the formation of mantle-derived magmas characterised by mantle-like δ18O (~ 6.0 to 5.5‰) and moderately positive εHf values (~ 4 to 1 εHf). As magmatism continued, transitional isotope signatures became predominant as melts of these disparate sources interacted and hybridised. It is proposed that under a compressional regime, mantle-derived magmas were halted in the lower continental crust, where they exchanged heat and volatiles with an older fertile lithosphere to generate melts from supracrustal sources. A shift in the stress regime at ca. 285 Ma permitted both crustally derived and juvenile mantle-derived magmas to exploit newly formed conduits to rise into the upper crust. A regional compilation of zircon O and Hf isotopes from felsic igneous rocks reveals a coherent secular trend over ~ 100 million years, where the oldest magmatism exhibits a dominant supracrustal component and younger magmas progressively (over 50 Ma) transition towards juvenile mantle-like isotopic compositions. This new dataset from Argentina fills a significant gap in the previous regional models between 285 and 250 Ma and documents the isotopic response of magmas produced in back-arc regions to a transition between compression and extensional/neutral stress regimes. These results give insight into the generation of new, or recycling of, continental crust in a back-arc setting and how the transition from compression to extension is imperative for ore-forming magmas to reach the upper crust.

El lujo tecnológico: Distinción y esnobismo en un contexto de prohibición: el consumo de Apple en Argentina (2015-2018) Correa, María Eugenia; Romani, Matias El presente trabajo pretende discutir el alcance de la categoría de “distinción” y su aplicación problemática al mundo de la tecnología digital. Para ello toma como universo de análisis a los consumidores de Apple en la Argentina durante el último trienio (2015- 1018), con el fin de comprender el impacto que impuso una circulación restringida de ciertos bienes sobre los valores corporativos que caracterizan a la marca. La hipótesis que se pretende demostrar es que recién a partir del 2010 –cuando se endurecieron las políticas en materia de importación de bienes tecnológicos– que la experiencia de consumo de Apple comenzó a percibirse como una estrategia de distinción entre los consumidores argentinos.; The present work intends to discuss the scope of the category of “distinction” and its problematic application to the world of digital technology. For this, it takes as a universe of analysis the Apple consumers in Argentina during the last three years (2015-2018), in order to understand the impact that imposed a restricted circulation of certain goods on the corporate values that characterize the brand. The hypothesis that is tried to demonstrate is that as of the 2010 –when the policies in the matter of importation of technological goods hardened– that the Apple’s consumer experience began to be perceived like a strategy of distinction among the Argentine consumers.; O presente trabalho pretende discutir o alcance da categoria de “distinção” e sua aplicação problemática ao mundo da tecnologia digital. Para isso, toma-se como universo de análise os consumidores da Apple na Argentina durante os últimos três anos (2015- 2018), a fim de compreender o impacto que impunha uma circulação restrita de certos bens nos valores corporativos que caracterizam a marca. A hipótese que se tenta demonstrar é que a partir de 2010 –quando as políticas em matéria de importação de bens tecnológicos se endureceram– que a experiência de consumo da Apple começou a ser percebida como uma estratégia de distinção entre os consumidores argentinos.

Fefferman–Stein Inequalities for the Hardy–Littlewood Maximal Function on the Infinite Rooted k-ary Tree Ombrosi, Sheldy Javier; Rivera Ríos, Israel Pablo; Safe, Martin Dario In this paper, weighted endpoint estimates for the Hardy–Littlewood maximal function on the infinite rooted k-ary tree are provided. Motivated by Naor and Tao [ 23], the following Fefferman–Stein estimate w({x∈T:Mf(x)>λ})≤cs1λ∫T|f(x)|M(ws)(x)1sdxs>1 is settled, and moreover, it is shown that it is sharp, in the sense that it does not hold in general if s=1⁠. Some examples of nontrivial weights such that the weighted weak type (1,1) estimate holds are provided. A strong Fefferman–Stein-type estimate and as a consequence some vector-valued extensions are obtained. In the appendix, a weighted counterpart of the abstract theorem of Soria and Tradacete [ 38] on infinite trees is established.

Carbonyl stretch of CH…O hydrogen-bonded methyl acetate in supercritical trifluoromethane Inafuku, Maximiliano Nelson; Marceca, Ernesto José Infrared spectroscopy in the gas phase was used to study the formation reaction of the CH⋯O hydrogen bonding complex involving the CH group of trifluoromethane, as a hydrogen donor, and the carbonyl group of methyl acetate, as a hydrogen acceptor, under different (T, p) conditions. The hydrogen-bonded carbonyl stretch of the molecular pair was monitored in dilute mixtures of methyl acetate in trifluoromethane at near-critical temperatures, from gas- to liquid-like densities. In the gas region, it was possible to discriminate the carbonyl signal of the hydrogen-bonded complex from that of the free ester and have access to their relative concentration. The equilibrium constant of the hydrogen bonding reaction and the standard enthalpy and entropy changes in the process were determined using the spectroscopic data. CH⋯O bonding was favored by lowering temperature or pressurizing F3CH in the mixture, remaining essentially no free carbonyl groups about the critical density. The carbonyl band of the hydrogen-bonded pair appeared as a single symmetric peak up to liquid-like densities, suggesting that the 1:1 methyl acetate-trifluoromethane complex has the most abundant stoichiometry. Spectral features as frequency shift and bandwidth of the hydrogen-bonded carbonyl were studied as a function of temperature and solvent-density. A bathochromic (red) vibrational shift was registered for the bound carbonyl band against density, with a sudden change in behavior in the near-critical region, while the width of this band remains mostly unresponsive.

Electroformation of coatings modified with silver on magnesium alloys for biomedical applications Loperena, Ana Paula; Forero Lopez, Ana Deisy; Brugnoni, Lorena Inés; Lehr, Ivana Leticia; Saidman, Silvana Beatriz Three different films modified with silver species were considered to enhance the corrosion resistance of AZ91D Mg alloy and to impart its surface with antibacterial activity. First, coatings were electrodeposited under potentiostatic conditions in electrolyte solutions containing Na2MoO4 and/or Ce(NO3)3 as main compounds, and H2O2, ascorbic acid or citric acid as additives. Incorporation of silver species was done by immersion of the samples in AgNO3 solutions. The obtained modified films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion protection properties of the films were examined in a simulated physiological solution by open circuit measurements, linear polarization and electrochemical impedance spectroscopy (EIS). The antibacterial effect of the coatings was evaluated using Escherichia coli bacteria. Cerium and molybdenum-based coating modified with silver provides superior antibacterial and anticorrosive properties compared to the other films studied.

La segmentación del trabajo en la Argentina: Un análisis de movilidad para los años de la post convertibilidad; Segmentation of work in Argentina: An analysis of mobility for the post-convertibility years Zuazua, Noemí Giosa; Fernández Massi, Mariana este artículo aborda la capacidad de los sectores de actividad con mejores empleos para absorber los empleos de subsistencia en un contexto de reducción de la tasa de desempleo y crecimiento de la actividad en la argentina. con este propósito se analizó la movilidad de los trabajadores entre cuatro segmentos de empleo. se construyeron matrices de transición anuales a partir de los datos de la encuesta permanente de Hogares correspondientes a los segundos trimestres de cada año, y se agruparon en dos períodos: 2004-2007, con fuerte crecimiento del empleo, y 2010-2013, un período menos dinámico. los resultados obtenidos sugieren que durante el primer período hubo transiciones desde los segmentos de micro producción hacia el segmento mediano/grande, pero las probabilidades de acceder a esos puestos fue mayor para quienes se encontraban en el segmento micro productivo. si bien se observa un leve proceso de movilidad ascendente hacia empleos de mejor calidad, también se observan transiciones desde la inactividad o desempleo hacia actividades de subsistencia, que amplían los excedentes de fuerza de trabajo.; this article deals with the capacity of the activity sectors with better working conditions in order to absorb employment of subsistence in a context of reduction of the unemployment rate and growth of the argentinian economy. to this end, four segments of the workers´ mobility were analyzed. annual transition matrices were calculated on the basis of the data obtained from the epH (permanent Household survey) during the second trimesters of each year, where two periods were grouped together: 2004-2007 –characterized by the dynamic growth of employment– and 2010-2013 –a period of low creation of jobs. the results reveal that during the first period there were transitions from the micro-production segments towards the large/medium segment, but the probabilities of having access to these jobs were higher for workers belonging to the micro-productive sector. although there is a slight upward mobility process towards jobs of higher quality, it is also observed that there is mobility from inactivity or unemployment towards subsistence activities, which extends the surplus of the working force.

The Relationship between a Western Amazonian Society and Domesticated Sedges (Cyperus spp.) Kujawska, Monika; Zamudio, Fernando; Albán Castillo, Joaquina; Sosnowska, Joanna The article discusses the relationships between the Ashaninka people from Peruvian Amazonia and the domesticated sedges (Cyperus spp.) cultivated in almost every Ashaninka home garden, and mostly exchanged within family circles. An over-differentiation phenomenon is observed, in which four species of Cyperus correspond to 86 folk species. The names of folk species are formed by secondary lexemes, composed of a semantically active constituent and a generic suffix (i)benki. The names contain mnemonic cues to differentiate otherwise morphologically similar plants, and their meanings correspond to Ashaninka ontological categories, thus revealing many levels of connectivity between them and non-humans. The wide scope of specific uses (approx. 60 registered) assigned to Cyperus spp. is only partly supported by phytochemicals and ergot alkaloids in the fungus-infested sedges. The key to understanding the ibenki?s (Cyperus) agency lies in local cosmologies, in which domesticated sedges are viewed as plant-persons and kin. The Ashaninka are engaged in producing the bodies of their kin, the ibenki. Simultaneously, ibenki are powerful allies in restoring harmonious social relations and protecting people against the intentional actions of other humans and non-humans.; El presente artículo analiza las relaciones entre el grupo asháninka de la Amazonía peruana y las juncias domesticadas (Cyperus spp.). Estas son plantas cultivadas en casi todos los huertos hogareños asháninka, y son mayormente intercambiadas dentro de los círculos familiares. Se observa un fenómeno de sobrediferenciación, en el que cuatro especies de Cyperus corresponden a 86 taxones vernáculos (etnoespecies). Los nombres de los taxones vernáculos están formados por lexemas secundarios, compuestos por un componente semánticamente activo y un sufijo genérico (i)benki. Los nombres contienen señales mnemotécnicas para diferenciar plantas morfológicamente similares, y sus significados corresponden a categorías ontológicas asháninka, revelando diversos niveles de conectividad entre los asháninkay no humanos. La amplia gama de usos específicos (aprox. 60 registrados) asignados a Cyperus spp. sólo están parcialmente respaldados por factores fitoquímicos propios de los alcaloides del cornezuelo de centeno que se encuentran en los hongos que infestan las juncias domesticadas. La clave para entender la agencia de los ibenki (Cyperus) se encuentra en las cosmologías locales, en las que las juncias domesticadas se consideran personas-plantas y parientes de los asháninka. En este sentido los asháninka se dedican a producir los cuerpos de sus parientes, los ibenki. Simultáneamente, los ibenki son aliados poderosos necesarios para restaurar relaciones sociales armoniosas y proteger a las personas contra las acciones intencionales de otros humanos y no humanos

Traits and impacts of introduced species: a quantitative review of meta-analyses Boltovskoy, Demetrio; Correa, Nancy Myriam; Burlakova, Lyubov E.; Karatayev, Alexander Y.; Thuesen, Erik V.; Sylvester, Francisco; Paolucci, Esteban Marcelo Despite significant growth in the information on introduced species (NIS), agreement on their comparative fitness and effects on native (NAT) communities is heterogeneous. Hypotheses aimed at explaining their fitness and impacts are as often supported as challenged. In order to investigate whether origin is associated with fitness or impact, we reviewed 72 meta-analyses of trait differences between NAT and NIS, and impacts of NIS on NAT and the environment, covering terrestrial and aquatic organisms. Interpretation of the trends was based on overall meta-analysis conclusions, and on numbers of point estimates (individual effect sizes) within and across studies. Mixed results were found in 44% of the studies. Higher NIS fitness and significant impacts were found in 31%, and 25% concluded that significant outcomes are largely absent. Point estimates showed that non-significant outcomes (57%) are more common than significant ones. Two thirds yield mixed trait differences and impacts, or do not support the concept that NIS are more fit or have negative effects on NAT. When trait differences or impacts are significant, NAT are usually less fit, or are negatively impacted, but this trend is influenced by the fact that most surveys are based on the most damaging invasive species.

Influence of various parameters in the seismic soil-structure interaction response of a nuclear power plant de Borbon, Fernanda Maria; Domizio, Martin Norberto; Ambrosini, Ricardo Daniel; Curadelli, Raul Oscar This paper presents a numerical study of the influence of various parameters on the seismic response of the CAREM-25 nuclear power plant (NPP) located in Argentina. The influence of soil stiffness, structure-soilstructure interaction (3SI), and infill soil stiffness are studied. Considering the available analysis capabilities, a full 3D methodology was adopted (direct method). Two soil profiles were used in order to quantify the influence of the soil on the structural response. An engineered rockfill was also used in order to study the influence of infill soil stiffness. Three artificial records with three components each were used as free field input. These records were obtained from the site design spectra. The turbo-group building was approximately modelled in order to consider 3SI. Finally, all live loads as well as the water in pools were included in the model. Design guides for this type of problem are given for all the elements of the model. When comparing flexible soil with stiff soil, important reductions of the maximum absolute acceleration value are obtained by flexible soil. Moreover, the horizontal maximum accelerations are remarkably amplified in height in the case of stiff soil. The influence of the proximity of the turbo-group building (3SI) on the dynamic response of the reactor building is negligible. Finally, the influence of infill soil stiffness is also negligible.

Las Escuelas Normales creadas para formar maestros/as rurales (Argentina, 1903-1952); Normal Schools created to train rural teachers (Argentina, 1903-1952) Rodríguez, Laura Graciela En este artículo analizaremos los distintos intentos de creación de Escuelas Normales destinadas a formar maestros/as rurales, impulsados por el Estado nacional, desde 1903 hasta 1952, haciendo foco en el curso de magisterio del nivel medio. Con base en la lectura de documentos oficiales, pretendemos mostrar que el proceso de creación de estas Normales puede ser comprendido en tres etapas (1903-1914; 1910-1930; y 1932-1952) que veremos por separado en cada apartado. Estudiaremos las distintas denominaciones que recibieron estas escuelas en cada momento (Regionales, de Preceptores y de Adaptación Regional) y los cambios que las afectaron a lo largo del tiempo.; In this article we will discuss different intents of creation of Normal Schools, destined to train rural teachers, made by National State from 1903 to 1952, focusing on the Normal Course (middle level). Based on the reading of official documents, we intend to show that the process of creating these Normal Schools can be understood in three stages (1903-1914; 1910-1930; and 1932-1952) that we will see separately in each section. We will study the different denominations that these schools received at all times (Regional, Preceptors and Regional Adaptation) and the changes that affected them over time.