A new Pliocene true toad (Anura: Bufonidae): first record of an extinct species from South America Pérez Ben, Celeste Marina; Gómez, Raúl O.; Báez, Ana M. Bufonids, known as true toads, constitute a very specious clade of hyloid neobatrachian frogs with an almost cosmopolitan distribution. Despite they are currently a major component of the extant anurofauna of South America, their fossil record there is still scarce and consists mostly of isolated bones assigned to extant species or regarded as indeterminate species, shedding little light on the evolution of the group. Herein we describe a new species of Rhinella, R. loba, from the Chapadmalalan (late Pliocene) of the Pampean Region of Argentina based on a partial skull. Rhinella loba is closely related to the species of the R. marina group but differs from all extant species of this group, constituting the first indisputable extinct bufonid species from South America. Its morphology suggests a close relationship with R. arenarum, the only extant species of the R. marina group currently inhabiting the South American Pampas. According to this hypothesis, R. loba is part of the stem lineage of R. arenarum is nested within the crown group of the R. marina group. Noteworthy, the late and early Pliocene ages of the new species and the earliest certain records of R. arenarum, respectively, are consistent with the previous estimated divergence of R. arenarum from its closest extant relatives during the earliest Pliocene around 5 Ma. In this regard, R. loba bridges the gap in the lineage towards R. arenarum, providing evidence of greater bufonid diversity in Buenos Aires province in Late Cenozoic times.

Habitat characteristics, hydrology and anthropogenic pollution as important factors for distribution of biota in the middle Paraná River, Argentina Blettler, Martin Cesar Maria; Oberholster, Paul Johan; Madlala, Tebogo; Eberle Folmer, Eliana Gisel; Amsler, Mario Luis; De Klerk, Arno R.; Truter, Johannes C.; Marchese Garello, Mercedes Rosa; Latosinski, Francisco Guillermo; Szupiany, Ricardo Nicolas The regulation of anthropogenic pollution inputs into large rivers is an important aspect of ecological resilience of aquatic systems and river pollution management. The current study examined the relationship between contamination loads, hydrological and morphological patterns and the distribution of macroinvertebrates and epipelic diatoms in the middle Paraná River system to form part of the development of a pollution monitoring framework. Seven sampling sites were selected over three main river areas predominantly impacted by sewage effluent and agriculture activities. The sampling areas were the Paraná, Colastiné and Las Conchas rivers. In order to prevent dilution of pollutants and macroinvertebrate drift, sampling was performed during the base flow period of 2015 to determine pollution contaminated stretches of the river system. Results indicated that metals have been accumulated in river bottom sediments as a consequence of anthropogenic land use activities. Macroinvertebrate and epipelic diatom assemblages as bioindicators of anthropogenic pollution were evident downstream of urban sewage effluent discharges causing higher concentrations of Cr, As and Ni than the permitted threshold levels for bottom sediment.

On stability measures and effects of data structure in the recognition of areas of endemism Casagranda, Maria Dolores; Goloboff, Pablo Augusto Incomplete data sampling, bias, and like properties of distribution datasets that potentially introduce uncertainty in biogeographical analyses and blur biogeographical patterns; therefore, it is important to understand their influence. Despite their relevance, these problems have been largely overlooked in biogeography, where concepts such as ambiguity, stability or support have not even been defined. Here, we propose two stability measures for hypotheses of areas of endemism (AEs) and use them to explore the degree to which different structural qualities of data affect the results of analyses of endemism. Our findings suggest that different types of data incompleteness have different effects on the recovery of the species composition and the geographical or spatial structure of AEs, showing that distinct levels of sampling coverage affect the stability of results in different ways. We show that a small proportion of poorly sampled species may have a stronger impact on AEs stability than many species with medium sampling and that excluding poorly sampled species from the analyses does not guarantee more stable results. These results highlight the importance of planning data collection and indicate that, in order to obtain more stable results, focusing on completing the distribution of strongly undersampled species might be preferable to adding records of any species randomly.

Endemism of lizards in the Chihuahuan Desert province: An approach based on endemicity analysis Ocampo Salinas, José Manuel; Castillo Cerón, Jesús M.; Manríquez Morán, Norma; Goyenechea, Irene; Casagranda, Maria Dolores Biogeography is the discipline that studies present and past distribution patterns ofbiological diversity and their underlying environmental (ecological) and historical causes(Sanmartín, 2012). It is known that different geological and climatic events occurring in thepast affect the distributions of co-existing taxa over time, establishing correlateddiversification patterns and groups of taxa from different time slices (divergence times) in asingle area of endemism (Morrone et al., 2016; Noguera-Urbano, 2016). Areas ofendemism (AEs) are the basic units in historical biogeographic studies (Morrone, 1994), aswell as for conservation biology (Whitakker et al., 2005), and are the result of taxaevolutionary processes (for example, vicariance/allopatric speciation). An area ofendemism is identified by the congruent distribution of two or more taxa (Platnick, 1991;Morrone, 1994; Szumik et al., 2002). Thus, taxa that have similar geographicaldistributions may have been influenced by common historical factors (Szumik et al., 2002).The Chihuahuan Desert (hereafter CD) is a biogeographic province that encompasses thenorthern region of Mexico and it is limited by the Sierra Madre Occidental and the SierraMadre Oriental provinces (Morrone, 2005, 2017). It is characterized by xeric environmentsand forests in high altitudes. The geographical extension of CD has enabled severalgeographical regionalization approaches. The identity of the CD as a natural region hasbeen supported by biogeographical analyses of different taxa: reptiles (Smith, 1941),mammals (Goldman and Moore, 1945), plants (Rzedowski, 1978; Arriaga et al., 1997),insects (Morrone, 1999, 2002, 2004 a, b) and it has been also delimited by applyingmorphotectonic criteria (Ferrusquía-Villafranca, 1990).In the last decades, different methods have emerged to identify EAs (Szumik et al., 2002;Szumik and Goloboff, 2004; Oliveira et al., 2015), and several problems have arisen in theidentification of AEs related to the use of different criteria of spatial congruence betweenspecies required to conform an AE. This issue has been discussed in different studies(Casagranda et al., 2009; Aagesen et al., 2013; Szumik and Goloboff, 2015; Szumik et al.,2018). The Endemicity Analysis (EA), implemented in the NDM/VNDM software, is oneof the most effective methods for identifying areas of endemism because it evaluates spatialcongruence of taxa over a set of cells (Szumik et al., 2002; Szumik and Goloboff, 2004)and considers the general concept of areas of endemism. EA identifies nested, overlappingand disjoint areas (Carine et al., 2009; Casagranda et al., 2009, 2012) and allows a varietyof analytical possibilities (see Escalante et al., 2013; Weirauch et al., 2016), including theuse of higher taxa for the identification of AEs, showing that some AEs recognized byspecies-level taxa also adjust well to the distribution of other higher level taxa i. e. genera,family (Szumik and Goloboff, 2015).Different studies using EA have been performed in northern Mexico (including theChihuahuan Desert, CD) with mammals (Escalante et al., 2007, 2009, 2010, 2013), insects(Rivas-Soto, 2011) and reptiles (Fernández-Badillo, 2013), but lizards have never beenincluded in EA studies as a group. Moreover, most of previous analyses have beenrestricted to northern Mexico without considering the distribution of taxa in the UnitedStates, limiting the endemicity patterns to geopolitical boundaries, which may not resemblenatural patterns. Because of this, Morafka, (2012) suggested that biological, ecological andphysiographic characteristics, as well as the total spatial distribution of taxa, should be usedto better characterize the naturalness of the CD in a historical biogeographic frame(Morrone et al., 2005).The main goal of this paper is to identify areas of endemism in the CD, using 81 species oflizards distributed throughout the province, by applying the EA implemented inNDM/VNDM software (Goloboff, 2004). The data are analyzed under different geographicscales (cell sizes) and using higher taxa (genera and families) together with species asanalytical units, in order to explore patterns at different taxonomic levels. We searched forthe times of divergence of endemic taxa in those AEs with high endemicity values, in orderto reconstruct the history of areas of endemism through time (Riddle et al., 2008).

Subcontratación, estrategias sindicales y calidad del empleo en la industria petroquímica; Outsourcing, union’s strategies and employment quality in the petrochemical industry Fernández Massi, Mariana El objetivo de este artículo es analizar las implicancias de la subcontratación sobre la calidad del empleo a partir del caso de dos empresas petroquímicas en la Argentina. Se ofrece un abordaje cualitativo, basado en el análisis documental y de entrevistas en profundidad. Se exploran tres dimensiones en las cuales se expresa la degradación del empleo: la (in)estabilidad del empleo; los niveles salariales; y un conjunto de condiciones de trabajo ?no pecuniarias? que comprenden diferentes derechos y/o beneficios laborales. Los resultados evidencian que, si bien persisten diferencias salariales y de estabilidad entre trabajadores directos y tercerizados, la estrategia sindical ha logrado reducir las heterogeneidades. A su vez, se destaca el modo en que diferencias referidas a otros beneficios como el comedor o el transporte son enfatizadas por los trabajadores tercerizados.; The objective of this article is to analyze the implications of outsourcing on employment quality in two petrochemical companies in Argentina. The study is based on the analysis of documents and in­depth interviews. Three dimensions ­which reveal the levels of employment degradation­ are explored: job (in)stability, wage levels and a set of working conditions ­non pecuniary­ which comprise different labor rights and/or employment benefits. The results reveal that, in spite of the different wages and levels of stability among direct and outsourced workers, the unions’ strategy has managed to reduce heterogeneities. Likewise, the study stresses that way in which other perks differences, as eating at the workplace or transport to and from work, are highlighted by outsourced workers.

El velo meritocrático: inequidades en la inserción laboral de jóvenes durante el gobierno de Cambiemos; O véu meritocrático: Iniqüidades na inserção de jovens no mercado de trabalho durante o governo de Cambiemos Busso, Mariana; Perez, Pablo Ernesto En un contexto signado por el discurso que preconiza el mérito individual, este artículo se propone analizar la relación entre educación, origen social, género e ingreso al mundo del trabajo de los y las jóvenes en Argentina, durante la presidencia de Mauricio Macri. En sintonía con el discurso meritocrático, si para analizar el ingreso de los y las jóvenes al mercado laboral tomamos en consideración únicamente variables educativas, observaremos que quienes poseen mayor nivel de educación generalmente presentan mayores tasas de actividad y empleo, y menores tasas de desempleo. Sin embargo, estudios anteriores permiten afirmar que dicha relación no es evidente, y que resulta insuficiente analizar únicamente la educación como variable explicativa clave para comprender el acceso a un puesto de trabajo. El género y el lugar en la estructura social, más allá del nivel educativo que detenten los y las jóvenes, son variables centrales en la construcción de escenarios de oportunidades. Para responder a nuestro objetivo analizaremos el período del gobierno de Cambiemos (iniciado en diciembre de 2015) a través de datos de la EPH-INDEC correspondientes al año 2017. Partimos del supuesto que existen marcadas diferencias en las posibilidades de acceso al mercado de trabajo según el estrato de ingresos del hogar, aun cuando se trate de jóvenes con igual nivel educativo. En ese sentido nuestra hipótesis sostiene que, durante el gobierno de Mauricio Macri, a pesar que el discurso oficial se centró en el mérito y el esfuerzo individual para mejorar la situación laboral, la realidad del mercado laboral está muy lejos de responder a una lógica meritocrática.; Em um contexto marcado pelo discurso que enfatiza o mérito individual, este artigo tem como objetivo analisar a relação entre educação, origem social, gênero e inserção no mundo do trabalho dos jovens na Argentina, durante a presidência de Maurício Macri. Em linha com o discurso meritocrático, si discutimos a entrada dos jovens no mercado de trabalho considerando apenas variáveis educacionais, vemos que aqueles com níveis mais elevados de educação geralmente têm maiores taxas de actividade e de emprego e as taxas de desemprego mais baixas. No entanto, estudos anteriores nos permitem afirmar que essa relação não é evidente, e que é insuficiente analisar apenas a educação como variável explicativa chave para entender o acesso a um emprego. Gênero e lugar na estrutura social, além do nível educacional dos jovens, são variáveis centrais na construção de cenários de oportunidades. Para cumprir nosso objetivo, analisaremos o período do governo de Cambiemos (desde dezembro de 2015) através de dados do EPH­INDEC para o ano de 2017. Nós assumimos que há diferenças marcantes nas possibilidades de acesso ao mercado de trabalho de acordo com o género e o estrato de renda familiar, mesmo quando se trata de jovens com o mesmo nível educacional. Nesse sentido, nossa hipótese sustenta que, durante o governo de Mauricio Macri, embora o discurso oficial tenha se centrado no mérito e no esforço individual para melhorar a situação do trabalho, a realidade do mercado de trabalho está longe de responder a uma lógica meritocrática.

Detection and molecular characterization of Chlamydia psittaci and Chlamydia abortus in psittacine pet birds in Buenos Aires province, Argentina; Detección y caracterización molecular de Chlamydia psittaci y Chlamydia abortus en psitácidos mascotas en la provincia de Buenos Aires, Argentina Origlia, Javier Anibal; Cadario, Maria E.; Frutos, Maria Celia; Lopez, Norberto F.; Corva, Santiago; Unzaga, Maria Florencia; Piscopo, Miguel Victor; Cuffini, Cecilia Gabriela; Petruccelli, Miguel Angel In order to determine the presence and genetic diversity of Chlamydia spp. in the north-eastern area of Buenos Aires province, Argentina, conjunctival, oropharyngeal, cloacal swab and tissues were collected from a total of 90 psittacine pet birds of different age and clinical manifestations. Through molecular methods, Chlamydiaceae was detected in 30% (27/90) of the samples, out of which 70.3% (19/27) were positive for Chlamydia psittaci and 14.9% (4/27) for Chlamydia abortus. Nine C. psittaci positive samples were genotyped by ompA gene sequences, 8 clustered within genotype A and 1 within genotype B. A significant association was observed between the presence of Chlamydia spp. and the manifestation of clinical signs compatible with chlamydiosis, as well as with the age of the birds (younger than one year old). This report contributes to the improvement of our understanding of chlamydial agents in our country.; Con el objetivo de determinar la presencia de Chlamydia spp. en psitácidos del área noreste de la provincia de Buenos Aires y conocer su diversidad genética, se recolectaron y analizaron mediante métodos moleculares hisopados conjuntivales, orofaríngeos, cloacales y tejidos de un total de 90 psitácidos de diferentes edades y con diversas manifestaciones clínicas. El 30% (27/90) de las muestras procesadas fueron positivas para Chlamydiaceae; el 70,3% (19/27) de estas resultaron positivas para Chlamydia psittaci y el 14,9% (4/27) para Chlamydia abortus. Nueve muestras positivas para C. psittaci fueron genotipificadas por secuenciación del gen ompA: 8 correspondieron al genotipo A y una al genotipo B. Se observó una asociación significativa entre la presencia de Chlamydia spp. y la manifestación de signos clínicos compatibles con clamidiosis, como así también con la edad de las aves (menores de un ano). ˜ Este informe contribuye a mejorar nuestro conocimiento de los agentes clamidiales en nuestro país.

La institucionalización del oficio de pedagogizar los cuerpos: el nacimiento de la formación profesional en Educación Física en Argentina (1897-1912); A institucionalização do oficio de pedagogizar os corpos: o nascimento da formação profissional de Educação Física na Argentina (1897-1912); The institutionalization of the corporal pedagogy profession: the birth of certified teachers of Physical Education in Argentina (1897-1912); L’institutionnalisation du métier de la pédagogie du corps: la naissance de la formation professionnelle en éducation physique en Argentine (1897-1912) Galak, Eduardo Esta indagación aborda una problemática histórica cuyos efectos no dejan de ser actuales: las disputas por la legitimidad del oficio de la Educación Física. Se reflexiona sobre cómo se gestó esta práctica en Argentina y cómo la institucionalización de la profesionalización garantizó su reproducción. De allí que se estudien los discursos dominantes del pasaje del siglo XIX al XX y cómo de ellos resultaron dos posicionamientos epistémicos claramente definidos, uno de corte “militarista” y otro “cívico-pedagógico”. Organizado en base a cinco acontecimientos cruciales en la institucionalización del oficio de la Educación Física que sucedieron entre 1898 y 1912, se analizan las voces contemporáneas de diferentes agentes ligados a la pedagogización de prácticas corporales en la Argentina.; Este artigo aborda uma problemática histórica cujos efeitos são ainda atuais: as disputas sobre a legitimidade do oficio da Educação Física. Reflete-se sobre como essa prática foi desenvolvida na Argentina e como a institucionalização da profissionalização garantiu sua reprodução. Estudou-se os discursos dominantes da passagem do século XIX ao XX dos quais resultaram em duas posições epistêmicas claramente definidas, uma de estilo “militarista” e a outra “cívico-pedagógica”. Tendo como base cinco processos importantes da institucionalização do oficio de Educação Física ocorridos entre 1898 e 1912, neste texto analisam-se as vozes contemporâneas de diferentes agentes relacionados à pedagogia das práticas corporais na Argentina no momento em tela.; This research analyzes a historical problem which results are still effectives: the disputes over the legitimacy of the profession of Physical Education. The intention is to think how this practice was conceived and how it institutionalization guaranteed its reproduction. For that, dominant discourses of the passage from the 19th to the 20th century are studied, and how from that resulted two clearly defined epistemic positions, one "militaristic" and the other "civic-pedagogical". Organized on the basis of five crucial events that took place between 1898 and 1912 about the institutionalization of the professionalization of Physical Education, it is analyze the contemporary voices of different agents linked to the pedagogization of corporal practices in Argentina.; Cette analyse aborde un problème historique dont les effets se ressentent encore aujourd’hui: les conflits sur la légitimité du métier de l’éducation physique. Le but est de retracer la manière dont ces pratiques se développent en Argentine et comment l’institutionnalisation de la profession a garanti sa reproduction. Les discours dominants du tournant des XIXe et XXe siècles sont étudiés et nous verrons comment cela a abouti à deux positions épistémiques clairement définies, l’une militaire et l’autre civique-pédagogique. Organisé sur la base de cinq événements cruciaux qui ont eu lieu entre 1898 et 1912, autour de la professionnalisation de l’éducation physique, cet article analyse les voix contemporaines de différents agents liés à la pédagogie des pratiques corporelles en Argentine.

Aportes de la concepción pedagógica de Francisco Ruiz Sánchez para una teoría motivacional perfectiva; Contributions of the pedagogical conception of Francisco Ruiz Sánchez for a perfective motivational theory Di Marco, María Elisa; Portela, Analía Inés; Gonzalez, Mariela Lourdes; Boarini, María Gisella; Difabio de Anglat, Hilda El presente trabajo pretende señalar algunos aspectos que permiten comprender a la motivación a partir de la plenitud dinámica, esto es, desde misma finalidad del acto educativo. Esta investigación ofrece un análisis de la motivación humana en el proceso de aprendizaje a la luz del pensamiento antropológico de Francisco Ruiz Sánchez. Detallaremos mediante una metodología hermenéutica de sus escritos publicados e inéditos los tres aspectos principales del proceso motivacional educativo: a) la metodología empleada, b) la propuesta de objetos buenos, y c) la concientización del valor del objeto. Se concluye que la motivación constituye un aspecto relacional en el marco de un proceso en el que interviene la cognición o tendencia intelectual hacia un objeto de conocimiento bueno, presentado de una manera sensible y que logra ser percibido como valioso por el educando.; The present work pretends to indicate some aspects that allow to understand the motivation from the dynamic fullness, that is, from the same purpose of the educational act. This research offers an analysis of human motivation in the learning process in light of the anthropological thinking of Francisco Ruiz Sánchez. We will detail through a hermeneutical methodology of his published and unpublished writings the three main aspects of the educational motivational process: a) the methodology employed, b) the proposal of good objects, and c) the awareness of the value of the object. It is concluded that motivation constitutes a relational aspect within the framework of a process involving cognition or intellectual tendency towards a good knowledge object, presented in a sensitive way and that can be perceived as valuable by the learner.

Fractional order Orlicz-Sobolev spaces Fernandez Bonder, Julian; Salort, Ariel Martin In this paper we define the fractional order Orlicz-Sobolev spaces, and prove its convergence to the classical Orlicz-Sobolev spaces when the fractional parameter s↑1 in the spirit of the celebrated result of Bourgain-Brezis-Mironescu. We then deduce some consequences such as Γ−convergence of the modulars and convergence of solutions for some fractional versions of the Δ g operator as the fractional parameter s↑1.

Deoxycholate-TPGS mixed nanomicelles for encapsulation of methotrexate with enhanced in vitro cytotoxicity on breast cancer cell lines Bernabeu, Ezequiel Adrian; Gonzalez, Lorena; Cagel, Carlos Maximiliano; Moretton, Marcela Analía; Chiappetta, Diego Andrés Biocompatible mixed nanomicelles consisting of sodium deoxycholate and D-α-tocopheryl polyethylene glycol 1000 succinate have been prepared in different molar ratios (100:0, 75:25, 50:50, 25:75 and 0:100) in order to improve the aqueous solubility and in vitro anti-tumor activity of methotrexate. The nanomicelles loaded with methotrexate were prepared without using any organic solvents and characterized in terms of critical micellar concentration, particle size and drug solubilization capacity of the micellar dispersion. The optimized formulation (ratio 25:75) exhibited a spherical shape and a particle size of about 8 nm. The results of the in vitro release assay showed that the micellar system presented a sustained release behaviour compared to the solution of methotrexate. Cell viability studies in MCF-7 and MDA-MB-231 cells revealed that mixed micelles achieved lower IC 50 values, in comparison to methotrexate and pralatrexate solutions. The formulated system showed a significant increase in the methotrexate cellular uptake, when compared to the free drug in both cell lines. Furthermore, hemolytic assay confirmed that methotrexate-loaded mixed micelles are compatible with red blood cells. Therefore, the mixed micelles developed in this study might be a potential nano-drug delivery system capable of overcoming in vitro resistance to methotrexate in breast cancer cells.

A mode of truth: Borges y la biografía en tres episodios Fontana, Patricio Miguel Evaristo Carriego, uno de los libros fundamentales del primer Borges, es, de un modo no ortodoxo, una biografía. Historia universal de la infamia es, también a su modo, una colección de biografías. Por su parte, Borges incluyó en El Aleph la biografía de un personaje ficcional: el sargento Cruz. En razón de esto, y de otros textos donde Borges reflexiona sobre el género biográfico o incursiona en él, me interesará rastrear en su obra cuál es su concepción del género biográfico y, en este sentido, cuál es la relación entre escritura y vida que se postula en ella.

In vitro breeding: Application of embryonic stem cells to animal production Goszczynski, Daniel E.; Cheng, Hao; Demyda-Peyrás, Sebastian; Medrano, Juan F.; Wu, Jun; Ross, Pablo J. Embryonic stem cells (ESCs) are derived from the inner cell mass of preimplantation blastocysts. For decades, attempts to efficiently derive ESCs in animal livestock species have been unsuccessful, but this goal has recently been achieved in cattle. Together with the recent reconstitution of the germ cell differentiation processes from ESCs in mice, these achievements open new avenues for the development of promising technologies oriented toward improving health, animal production, and the environment. In this article, we present a strategy that will notably accelerate genetic improvement in livestock populations by reducing the generational interval, namely in vitro breeding (IVB). IVB combines genomic selection, a widely used strategy for genetically improving livestock, with ESC derivation and in vitro differentiation of germ cells from pluripotent stem cells. We also review the most recent findings in the fields on which IVB is based. Evidence suggests this strategy will be soon within reach.

Agricultura, cultura del oasis y megaminería en Mendoza: Debates y disputas; Agriculture, oasis' culture and mega-mining in Mendoza: Debates and disputes Wagner, Lucrecia Soledad Mendoza es una de las provincias argentinas donde el rechazo a la megaminería ha sido más exitoso. Este trabajo tiene como objetivo analizar la cultura mendocina del oasis como uno de los fundamentos de la oposición a esta actividad. Basándonos en fuentes documentales, producidas principalmente por el Estado provincial, y en un trabajo etnográfico que recupera testimonios de quienes se oponen a la megaminería, concluimos que el rechazo a esta actividad tiene un arraigo en ciertas características de la historia provincial, que combinadas con nuevas demandas socioambientales, han dado lugar a una de las resistencias a la megaminería más trascendentes de la Argentina.; Mendoza is one of the argentinean provinces where the rejection of the mega mining has been most successful. This work aims to investigate the oasis culture, as one of the basis of opposition to this activity. Based on documentary sources, produced mainly by the provincial government, and an ethnographic work that includes testimonies of the protagonists of mega mining rejection, we conclude that the rejection of this activity is rooted in certain provincial history characteristics, which combined with new social-environmental demands, have given rise to one of the most transcendent resistance to mega mining in Argentina.

Revocatoria de Mandato en Perú: diseño institucional y resultados de su aplicación; Recall in Perú: institutional design and results of its application Eberhardt, Maria Laura Desde fines de la década de 1980, tras la decadencia de los Estados de Bienestar y el auge de la democracia de audiencia, gran parte de las democracias occidentales ingresaron en una fase de “crisis de la representación”. Frente a dicho escenario, varios países latinoamericanos emprendieron reformas constitucionales en las que, entre otros cambios, se incorporaron mecanismos de participación ciudadana, como la revocatoria de mandato. Esta herramienta de accountability societal permite a los ciudadanos destituir a representantes electos a través del voto. Perú la incorporó en su Constitución de 1993 junto con otros instrumentos de democracia directa, aunque con alcance limitado a las autoridades de los ámbitos regional y local. Este país fue emblemático en el continente en cuanto a la frecuencia y cantidad de veces que utilizó el revocatorio, si bien no siempre con resultados deseables en términos de control ciudadano y superación de crisis de legitimidad de los gobernantes. Por el contrario, su uso indebido y en exceso ha provocado problemas de gobernabilidad a nivel local. En el presente artículo se analiza el diseño institucional de la revocatoria de mandato en Perú y sus resultados de aplicación, tanto positivos como negativos, para la calidad democrática y la estabilidad institucional.; Since the end of the 80s, after the decline of the Welfare States and the rise of the Hearing Democracy, a large part of Western democracies entered a phase of “crisis of representation”. Faced with this scenario, several Latin American countries undertook constitutional reforms in which, among other changes, citizen participation mechanisms were incorporated, such as the recall. This tool of societal accountability allows citizens to dismiss elected representatives through voting. Peru incorporated it in its Constitution of 1993 together with other instruments of direct democracy, although with limited scope to the authorities of the regional and local levels. This country was emblematic in the continent in terms of the frequency and number of times it used the recall, although not always with desirable results in terms of citizen control and overcoming legitimacy crises of the rulers. On the contrary, its undue and excessive use has caused problems of local governance. This article analyzes the institutional design of the recall in Peru and its results, both positive and negative, for the democratic quality and institutional stability.

Promoción estatal del cooperativismo de trabajo y formas socioproductivas emergentes: Contribuciones en clave emancipatoria a partir de un estudio de caso del Programa Argentina Trabaja; State promotion of worker cooperatives and emerging socioproductive forms: Contributions from an emancipatory perspective based on a case study of the Argentina Trabaja Program Kasparian, Denise Romina Desde comienzos del siglo XXI y hasta el año 2015, las cooperativas de trabajo en Argentina se expandieron en el marco de políticas públicas de fomento del cooperativismo y la economía social. A partir de un estudio de caso, el presente artículo se propone realizar una caracterización socioproductiva de una cooperativa creada por el Programa Argentina Trabaja que contribuya a una reflexión en torno a las limitaciones y potencialidades en términos emancipatorios que plantea esta vía de conformación y puesta en marcha de cooperativas que podríamos denominar ?incubada?. Para la realización del estudio de caso se triangularon una serie de técnicas de investigación: entrevistas en profundidad a trabajadores de la cooperativa, observación no participante y análisis documental. Sostenemos que la cooperativa analizada configura una forma de producción híbrida no mercantil con dominio del poder estatal, orientada a la reproducción de trabajadores excluidos del mercado laboral, que habilita ciertos grados de empoderamiento social a través de la autoapropiación privada-colectiva y los espacios de autodeterminación de los trabajadores, configurando esquemas asimilables a la cogestión. Indexada en: CONICET-CAICYT-Núcleo Básico.; Since the beginning of the 21st century and until 2015, worker cooperatives in Argentina have expanded within the framework of public policies that promote cooperativism and social economy. Based on a case study, the present article carries out a socio-productive characterization of a cooperative created by the Argentina Trabaja Program that contributes to a reflection on the limitations and potentialities in emancipatory terms of this path of conformation and start-up of cooperatives that could be called “incubated”. To carry out the case study, a series of research techniques were triangulated: in-depth interviews with workers of the cooperative, non-participant observation and documentary analysis. We argue that the analyzed cooperative constitues a nonmercantile hybrid form of production dominated by state power, aimed at the reproduction of workers excluded from the labor market, that enables degrees of social empowerment through private-collective self-appropriation and areas of self-management of workers, creating schemes similar to co-management.

Acid leaching of licoo2 from libs: thermodynamic study and reducing agent effect; Lixiviación ácida de licoo2 proveniente de libs: estudio termodinámico y del efecto de un agente reductor Pinna, Eliana Guadalupe; Martínez, A.A.; Tunez, Fernando Marcelo; Drajlin Gordón, Diego Sebastián; Rodriguez, M.H. This work shows the results of a comparative hydrometallurgical study of LiCoO2 leaching, obtained from the cathodesof spent lithium-ion batteries (LIBs), with HF and HF/H2O2. The operational parameters researched were H2O2 and HFconcentrations, solid-liquid ratio, stirring speed, temperature and reaction time. The experimental results indicated that the bestworking conditions, with dissolution values close to 100%, were 348 K, 330 rpm, 30 min, 8 g/L, HF 0.6 M and H2O2 0.7 M.Thermodynamic study of the dissociation of HF in aqueous solution and EH-pH diagrams for Li-H2O, Co-H2O and Li-Co-F-H2Osystems were performed. The results showed the feasibility of extracting and recovering metals contained in the sample.Keywords: LiCoO2, LIBs, reducing agent, thermodynamic

Búsquedas de vínculos eróticos y/o afectivos. Un estudio comparado entre la Ciudad de Buenos Aires y la Ciudad de México Palumbo, Mariana El artículo analiza, desde un enfoque cualitativo y de corte comparativo, por qué mujeres y varones heterosexuales adultas de clase media residentes de la Ciudad de Buenos Aires y de México eligen a las aplicaciones de citas, en este caso Tinder, como el espacio de sociabilidad a partir del cual llevar a cabo encuentros eróticos y/o afectivos. Para tal fin se describen y analizan: a) cuáles son las motivaciones – facilidades propias de la aplicación y aquellas de índole erótica y/o afectiva– que lleva a sus usuarios/as a utilizar Tinder; b) el uso geolocalizado que la aplicación ofrece: dónde sus usuarios/as la usan, cuáles son sus márgenes espaciales de búsqueda y cuál es su uso en otros países si los hubiera; c) el papel de las mujeres como consumidoras de las aplicaciones virtuales de citas.; This article employs a qualitative and comparative approach towards analyzing the reasons why middle-class adult heterosexual men and women residing in Buenos Aires and Mexico choose to use dating applications -in this case Tinder- as a space of sociability for the purpose of erotic and/or affective meetings. To that end, we shall describe and analyze: a) the motivations involved -conveniences, as well as erotic and/or affective features of the application- that attract users to Tinder; b) the geolocation feature offered by Tinder: where the application is used, the spatial scope of the searches performed, and if the application is used in other countries; c) the role of women as consumers of dating applications.

Monitoring of engine oil aging by diffusion and low-field nuclear magnetic resonance relaxation Förster, Eva; Fraenza, Carla Cecilia; Küstner, Jan; Anoardo, Esteban; Nirschl, Hermann; Guthausen, Gisela Time domain, also named lowfield nuclear magnetic resonance is used to monitor oil degradation by measuring relaxation and diffusion. As quality control of oils is indispensable to optimize oil change intervals while simultaneously preventing machinery damage, the technique was applied to detect the degradation state of engine oils as time domain nuclear magnetic resonance is known as a well suited tool to measure quality control parameters for example in food industry. Correlations with commonly applied oil analytics like viscosity measurements and inductively coupled plasma optical emission spectrometry allow to interpret relaxation and diffusion data in detail and finally to deepen the understanding of oil aging processes. Additionally, the measurement temperature was varied to achieve the maximum sensitivity towards oil aging. Low field NMR is not only realized in form of table top instruments, but also in form of field cycling and single sided NMR devices. Fast field cycling as well as single-sided NMR were also explored to study oil aging and to provide valuable insight. The latter device was used to obtain information about translational diffusion and transverse relaxation of oils simultaneously.

Grab recruitment by Rab27A-Rabphilin3a triggers Rab3A activation in human sperm exocytosis Quevedo, María Florencia; Bustos, Matias Alberto; Masone, Diego Fernando; Roggero Savoini, Carlos Marcelo; Bustos, Diego Martin; Tomes, Claudia Nora Sperm must undergo the regulated exocytosis of its dense core granule (the acrosome reaction, AR) to fertilize the egg. We have previously described that Rabs3 and 27 are organized in a RabGEF cascade within the signaling pathway elicited by exocytosis stimuli in human sperm. Here, we report the role of Rabphilin3a and GRAB, that link these secretory Rabs in the RabGEF cascade. Like Rab3 and Rab27, GRAB and Rabphilin3a are present, localize to the acrosomal region and are required for calcium-triggered exocytosis in human sperm. Sequestration of either protein with specific antibodies introduced into streptolysin O-permeabilized sperm impairs the activation of Rab3 in the acrosomal region elicited by calcium, but not that of Rab27. Biochemical and functional assays indicate that Rabphilin3a behaves as a Rab27 effector during the AR and that GRAB exhibits GEF activity toward Rab3A. Recombinant, active Rab27A pulls down Rabphilin3a and GRAB from human sperm extracts. Conversely, immobilized Rabphilin3a recruits Rab27 and GRAB; the latter promotes Rab3A activation. The enzymatic activity of GRAB toward Rab3A was also suggested by in silico and an in vitro assays with purified proteins. In summary, we describe a signaling module where Rab27A-GTP interacts with Rabphilin3a, which in turn recruits a GEF activity toward Rab3A. This is the first description of the interaction of Rabphilin3a with a GEF. Because the machinery that drives exocytosis is highly conserved, it is tempting to hypothesize that the RabGEF cascade unveiled here might be part of the molecular mechanisms that drive exocytosis in other secretory systems.