Characterization of chemical parameters in surface sediments from a semi-enclosed frontal system: The case of the San José Gulf, Patagonia Argentina Hernández Moresino, Rodrigo Daniel; Giarratano, Erica; Gil, Monica Noemi The San José Gulf (SJG) is a highly productive basin where a seasonal frontal system takes place, supporting a small-scale fishery on bivalves. In terms of benthonic resources, sediments and the overlying water column are strongly linked and both are affected by the prevalent bottom hydrodynamics. In this work, several chemical variables were assessed to evaluate sediment variability during the frontal system formation and were linked to grain size sediments and bottom water circulation. Four sectors were identified within SJG. Sector 1 comprises two reduced areas characterized by the highest contents of the studied chemical parameters (total organic matter, phytopigments, and total ammonium) due to low hydrodynamic conditions, which facilitate the sedimentation of fine grains and other particles. Sector 2 is characterized by moderate values of chemical parameters, encompassing the surrounding area of Sector 1. Sectors 3 and 4 represent the largest area of SJG, which show low concentrations of chemical variables associated with coarse-grain sediments and with the prevalence of high-energy hydrodynamic conditions. The higher amount of total organic matter in the whole SJG in spring than summer emphasizes the role of seasonal changes in temperate regions, with the formation of a thermocline during spring-summer. This is in concordance with the observed falling of redox potential in summer, suggesting consumption of the available oxygen by the activity of aerobic microorganisms and the transformation from oxidized to reduced sediments. Phytopigments and TOM were good descriptors of the environmental quality, being in the same order than those reported for marine coastal sediments in meso-eutrophic regions.

Historical shell form variation in Lottia subrugosa from southeast Brazilian coast: Possible responses to anthropogenic pressures Harayashiki, Cyntia Ayumi Yokota; Martins, Camila Pratalli; Márquez, Federico; Bigatti, Gregorio; Castro, Ítalo Braga Mollusk shells can provide important information regarding environmental parameters. It is known that shell morphology is affected by both natural and anthropogenic factors. However, few studies have investigated alterations in shell morphology over a historical perspective and considering chemical contamination and climate changes. The present study assessed shell form (shape and size) variations of limpet (Lottia subrugosa) shells sampled from 1950 to 1981 (past) in comparison with organisms obtained in 2018 (present). Differences between shells from the past and present (2018) were detected, being shell weight and height the two most important affected parameters. The differences observed were attributed to the possible increase in contamination over the years due to human population growth and to climate change. Additionally, when shells from the past were evaluated according to the decade they were sampled, results indicate that it was necessary an interval of 40 years to shell form be altered within populations.

Hacia una deconstrucción de la unión mujer-madre Giallorenzi, María Laura Este trabajo propone un abordaje sobre la maternidad basado en los campos disciplinares de la filosofía, la sociología, la historia y la psicología, así como de los estudios sobre género y las teorías desarrolladas por los feminismos. En este sentido, en un primer apartado, se busca definir y caracterizar a la maternidad, poniendo en discusión ciertos enfoques que, desde diversas perspectivas, han centrado su mirada crítica en la asociación unívoca entre mujer y maternidad y la reducción de la feminidad a la maternidad que se ha ido construyendo a lo largo de la historia.En un segundo apartado, se plantea como alrededor de la maternidad se gestan algunas discursividades y operaciones culturales que tienden a perpetuar la unión mujer-madre. Para dar lugar aldesentrañamiento de dichas operaciones culturales, se profundiza en la construcción socio-política de la maternidad, y con ella de las categorías de: maternalizacion de las mujeres, maternazgo y maternalismo. Este análisis, permite situar cómo se fuerongestando diferentes sistemas de legitimación de la maternidad como destino para todas las mujeres. El objetivo de pensar y conceptualizar a la maternidad bajo estas lecturas críticas, está dado en buscar, que la maternidad signifique también una experiencia de emancipación para las mujeres y un espacio por el cual obtener los derechos necesarios para ejercer dicho rol.

A free boundary problem for a diffusion–convection equation Briozzo, Adriana Clotilde; Tarzia, Domingo Alberto One-dimensional free boundary problem for a nonlinear diffusion - convection equation with a Dirichlet condition at fixed face x=0, variable in time, is considered. Throught several transformations the problem is reduced to a free boundary problem for a diffusion equation and the integral formulation is obtained. By using fixed point theorems, the existence and uniqueness of solution, for small time, to a system of coupled nonlinear integral equations is obtained.

De qué van las epistemologías críticas en la Ciencia Política Rovetto, Florencia Laura; Zanucolli, Mariel; Taruselli, María Victoria La presente discusión se enmarca en un proyecto de investigación cuyo principal objetivo consiste en relevar y sistematizar experiencias de investigadores que, desde el campo disciplinar de la Ciencia Política Argentina, apuestan a ensayar alternativas epistemológicas y metodológicas, con sentidos contrahegemónicos. Entre ellos, destacamos los insoslayables aportes de los feminismos para revisar la construcción de conocimientos en las Ciencias Sociales, en general, y en los presupuestos de la Ciencia Política, en particular. En primer lugar, centramos el eje de la discusión en sus cuestionamientos a las formas canonizadas de producción disciplinar, interpelando el vínculo de «los saberes politológicos» con los sujetos políticos y recuperando la posición del sujeto cognoscente como parte de la situación de investigación. En segundo lugar, proponemos criterios para sistematizar estas experiencias que nos permitan ensayar prácticas pedagógicas e institucionales capaces de alojar nuevas formas de producir conocimiento crítico y habitar las instituciones universitarias. De esta manera, intentamos transcender los mecanismos meramente reproductivos de su función, favoreciendo la interacción de la academia con el medio social, mediante objetivos de intelección crítica y transformadora.

Cómo afrontar la pandemia del Coronavirus (Covid-19) en las Américas: recomendaciones y líneas de acción sobre salud mental; Coping with the Coronavirus (Covid-19) pandemic in the Americas: recommendations and guidelines for mental health Gallegos de San Vicente, Miguel Omar; Zalaquett, Carlos; Luna Sánchez, Sandra Elizabeth; Mazo Zea, Rodrigo; Ortiz Torres, Blanca; Penagos Corzo, Julio C.; Portillo, Nelson; Torres Fernández, Ivelisse; Urzúa, Alfonso; Morgan Consoli, Melissa; Polanco, Fernando Andrés; Florez, Ana María; Lopes Miranda, Rodrigo El 11 de marzo del 2020 la Organización Mundial de la Salud declaró pandemia a la enfermedad ocasionada por el Covid-19, la cual provoca efectos tanto en la salud física como mental de las personas infectadas por el virus, así como en el personal sanitario que las asiste. Dada la escasa disponibilidad de guías y recomendaciones elaboradas por instituciones psicológicas a nivel continental para afrontar los efectos en la salud mental, investigadores de la Sociedad Interamericana de Psicología (SIP) se propusieron el objetivo de construir una guía de recomendaciones sobre diferentes temas y problemáticas psicológicas. Para esto, se realizó una revisión sistemática de la literatura científica referida a la afectación de la salud mental provocada por este tipo de pandemia. Con base en la información recuperada y analizada de diversas bases de datos científicos (PsycInfo, Scielo, Redalyc y Dialnet), fuentes documentales procedentes de organismos nacionales e internacionales de salud mental, consulta a expertos en salud mental y diversas investigaciones científicas, se redactó un documento orientador para afrontar las consecuencias emocionales y psicosociales del Covid-19. Se espera que este aporte sea de utilidad para orientar a la ciudadanía y las prácticas profesionales de los psicólogos y psicólogas, y se constituya en una herramienta que sustente la toma de decisiones en las organizaciones psicológicas y en los organismos gubernamentales en salud pública de los diferentes países de las Américas.; On March 11, 2020, the World Health Organization declared a pandemic caused by Covid-19, a disease that affects both the physical and mental health of people infected with the virus, as well the health personnel who assist them. Given the limited availability of guides and recommendations prepared by psychological institutions at a continental level to face the effects on mental health, researchers from the Inter-American Society of Psychology (SIP) have created some recommendations on different psychological issues and problems relate to the disease and pandemic. To accomplish this this, a systematic review of the scientific literature on mental health issues caused by this type of pandemic was carried out. Based on the information recovered and analyzed from various scientific databases (PsycInfo, Scielo, Redalyc and Dialnet), documentary sources from national and international mental health organizations, consultation with experts in mental health and various scientific investigations, we have created the following guiding document for facing the emotional and psychosocial consequences of Covid-19. It is hoped that this contribution will be useful in guiding both laypeople and professional psychologists, and will become a tool to support decision-making in psychological organizations and public health government agencies of different countries of the Americas.

Acceso, usos y problemas en la educación virtual: una aproximación a las experiencias de estudiantes y docentes durante la cuarentena obligatoria en Argentina; Access, uses and problems in virtual education: an approach to the experiences of students and teachers during compulsory quarantine in Argentina Hernández, Andrés Eduardo El presente artículo se propone reconstruir un estado de situación a partir de las experiencias y representaciones de docentes y estudiantes, durante el período de cuarentena obligatoria, en el contexto de la pandemia mundial por Covid-19. A partir de ello se intenta contribuir a profundizar el debate acerca de las transformaciones y problemáticas emergentes que están teniendo lugar en el marco de la llamada educación virtual, prestando especial ataención al actual escenario que se abre a la par de la implementación de políticas de confinamiento o aislamiento preventivo. Se espera que una lectura como esta, en clave de acceso, usos y problemas permita seguir de cerca las desigualdades que afectan a los países de nuestra región.; This article aims to reconstruct a state of a situation based on the experiences and representations of teachers and students, during the period of compulsory quarantine, in the context of the global pandemic by Covid-19. From this, an attempt is made to contribute to deepening the debate about the transformations and emerging problems that are taking place within the framework of the so-called virtual education, paying special attention to the current scenario that is opening up alongside the implementation of confinement policies or preventive isolation. It is expected that reading like this, in terms of access, uses, and problems will allow us to closely follow the inequalities that affect the countries of our region.

An influenza epidemic model with dynamic social networks of agents with individual behaviour López, Leonardo; Fernández, Maximiliano Andrés; Gómez, Andrea; Giovanini, Leonardo Luis There is an interplay between the spread of infectious disease and the behaviour of individuals that can be
modelled through a series of interconnected dynamical feedback blocks. Specifically, the outbreak of an infectious
disease can trigger behavioural responses, at the group and individual levels, which in turn influences
the epidemic evolution. Daily life interactions can be modelled through adaptive co-evolutionary networks
whose nodes represent the interconnected individuals. In this paper we introduce an individual-based model
where the behaviour of each agent is determined by both external stimuli and perception of its environment. It is
built as a combination of three interacting blocks that model the fundamental aspects of an epidemic: i) individual
behaviour, ii) social behaviour and iii) health state.

Cultura visual y pandemia: reflexiones acerca de un virus a la vista Dipaola, Esteban Marcos En el artículo se realiza una reflexión acerca de los efectos de la cultura visual global en la pandemia por Covid-19, atendiendo a cómo el virus aparece en el ámbito de lo visible y cuáles son las consecuencias sociológicas, políticas y culturales de la situación.

Mediatización de las epidemias: la cobertura sobre la pandemia de la gripe A (H1N1) de 2009 en Argentina, Estados Unidos y Venezuela; Mediatizing Epidemics: News Coverage of the A (H1N1) Influenza Pandemic of 2009 in Argentina, the United States and Venezuela Hallin, Dan; Briggs, Charles; Martini Briggs, Clara; Spinelli, Hugo; Sy, Anahi En este artículo se explora la mediatización de las epidemias como objeto de conocimiento público, mediante un análisis de contenido de las noticias sobre la gripe A (H1N1) de 2009 en Argentina, Estados Unidos y Venezuela. Los resultados indican que los periódicos siguieron los esfuerzos de las autoridades sanitarias de movilizar la atención pública y, simultáneamente, contener la alarma exagerada y los discursos sobre el virus.

La pandemia que estremece al capitalismo; The pandemic that shakes capitalism Katz, Claudio Isaac El coronavirus es una calamidad natural potenciada por el capitalismo, que a diferencia de la guerraexige protección y no destrucción de vidas humanas. Detonó las tensiones previas de la financiarización y la superproducción y precipitó los desequilibrios acumulados con laglobalización, la urbanización y el agro-negocio. La crisis irrumpió por ausencia de correlatos sanitarios de la mundialización. La contraposición negacionista entre salud y economía es falsa. Laactividad productiva puede adaptarse a la emergencia, mediante las regulaciones que rechaza eneoliberalismo. Las advertencias de la pandemia fueron ignoradas por la baja rentabilidad de su prevención y la competencia actual entre las farmacéuticas ha derivado en piratería entre losgobiernos. Mientras China contiene una infección que estalló por la expansión del capitalismo,Estados Unidos afronta el contagio en forma caótica. Ya abandonó su disfraz de auxiliador delmundo. La gestión nacional de la pandemia quebranta a la Unión Europea.; The coronavirus is a natural calamity powered by capitalism, which, unlike war requires protection and not destruction of human lives. It detonated previous tensions of financialization and overproduction and precipitated accumulated imbalances with globalization, urbanization, and agribusiness. The crisis erupted due to the absence of health correlates of globalization. The denialist contrast between health and economy is false. Productive activity can adapt to the emergency, through regulations that neoliberalism rejects. The pandemic's warnings were ignored because of the low cost effectiveness of its prevention, and current competition among pharmaceutical companies has led to piracy among governments. While China contains an infection that erupted due to the expansion of capitalism, the United States faces contagion in a chaotic way. He has already abandoned his disguise as a helper of the world. The national management of the pandemic breaks the European Union.

Fully Adaptive Ridge Detection Based on STFT Phase Information Colominas, Marcelo Alejandro; Kuppel, Sylvain; Pham, Duong-Hung This letter deals with the problem of the estimation of the instantaneous frequencies of the modes of multicomponent signals from their linear time-frequency representations. In most approaches, such an estimation consists of extracting the ridges associated with each mode in the time-frequency plane. A major issue associated with these techniques is that ridge detection relies on some ad-hoc parameters which essentially bound the modulation of the studied modes and put some constraints on the type of filter used in the time-frequency representation. In this paper, we alternatively propose a novel fully adaptive approach for ridge detection whose relevance is shown throughout numerical simulations.

Platelet toll-like receptors mediate thromboinflammatory responses in patients with essential thrombocythemia Marin Oyarzún, Cecilia Paola; Glembotsky, Ana Claudia; Goette, Nora Paula; Lev, Paola Roxana; de Luca, Geraldine; Baroni Pietto, Maria Constanza; Moiraghi, Beatriz; Castro Ríos, Miguel A.; Vicente, Angeles; Marta, Rosana Fernanda; Schattner, Mirta Ana; Heller, Paula Graciela Essential thrombocythemia (ET) is comprised among chronic myeloproliferative neoplasms (MPN) and is caused by driver mutations in JAK2, CALR and MPL, which lead to megakaryocyte proliferation and prominent thrombocytosis. Thrombosis remains the main cause of morbidity in ET and is driven by the interplay between blood cells, the endothelium, the clotting cascade and host-derived inflammatory mediators. Platelet activation plays a key role in the thrombotic predisposition, although the underlying mechanisms remain poorly defined. In addition to their role in hemostasis, platelets participate in innate immunity and inflammation owing to the expression of toll-like receptors (TLR), which recognize inflammatory signals, triggering platelet functional responses. Considering the impact of inflammation on ET procoagulant state, we assessed the contribution of TLR2 and TLR4 to platelet hemostatic and inflammatory properties in ET patients, by using Pam3CSK4 and lipopolysaccharide (LPS) as specific TLR2 and TLR4 ligands, respectively. TLR2 ligation induced increased surface translocation of α-granule-derived P-selectin and CD40L, which mediate platelet interaction with leukocytes and endothelial cells, respectively, and higher levels of dense granule-derived CD63 in patients, whereas PAC-1 binding was not increased and LPS had no effect on these platelet responses. Platelet-neutrophil aggregate formation was elevated in ET at baseline and after stimulation of both TLR2 and TLR4. In addition, ET patients displayed higher TLR2- and TLR4-triggered platelet secretion of the chemokine RANTES (CCL5), whereas von Willebrand factor release was not enhanced, revealing a differential releasate pattern for α-granule-stored inflammatory molecules. TLR-mediated hyperresponsiveness contrasted with impaired or preserved responses to classic platelet hemostatic agonists, such as TRAP-6 and thrombin. TLR2 and TLR4 expression on the platelet surface was normal, whereas phosphorylation of downstream effector ERK1/2 was higher in patients at baseline and after incubation with Pam3CSK4, which may partly explain the enhanced TLR2 response. In conclusion, exacerbated response to TLR stimulation may promote platelet activation in ET, boosting platelet/leukocyte/endothelial interactions and secretion of inflammatory mediators, overall reinforcing the thromboinflammatory state. These findings highlight the role of platelets as inflammatory sentinels in MPN prothrombotic scenario and provide additional evidence for the close intertwining between thrombosis and inflammation in this setting.

Description of the putative mature larva of the Neotropical genus Stenhelmoides Grouvelle (Coleoptera: Elmidae) Gonzalez Cordoba, Marcela; Martínez Román, Nicolás Rafael; Zúñiga, María del Carmen; Manzo, María Verónica; Archangelsky, Miguel Stenhelmoides Grouvelle is a Neotropical genus of Elmidae and although it exhibits a wide distribution, until now no larvae had been associated with adults of this genus. Larvae, very likely belonging to this genus, were associated based on co-occurrence with adults. Eleven larvae and nine adults were examined from ten localities at altitudes between 30 and 682 m a.s.l. in the Andean, Caribbean and Pacific regions in Colombia. Mature larvae of the Stenhelmoides rufulus (Hinton) are described and illustrated for the first time. A larval diagnosis for the genus is presented; body shape, distribution and form of setae and number of pleural sclerites are diagnostic characters for larvae of this genus. comparative notes with similar larvae of other elmidae genera are presented. the existing generic keys are updated to include larvae of Stenhelmoides. comments on distribution and habitat of Stenhelmoides larvae are also provided. This work contributes to enhance the knowledge of Neotropical larvae, which have have been described for only approximately 56% of genera and 8% of species of Elmidae.

Do small cities affect bird assemblages? An evaluation from Patagonia Gorosito, Cristian Andrés; Cueto, Víctor Most studies about the impact of urbanization on bird assemblages are from the Northern Hemisphere and most previous research has reported that cities reduced bird species richness and favored the settlement of exotic bird species. However, most of these studies took place in large cities and few of them were focused on riparian environments. The aim of our study was to investigate how richness and abundance of riparian birds change along the urban-rural gradient of Esquel, a small city in Patagonia. We established two rural riparian sites upstream, two urban riparian sites and two rural riparian sites downstream, and set up six point counts in each site. We counted birds twice (once in November 2013 and January 2014) and sampled vegetation coverage at each point count location. We used GLMMs to analyze data. Bird species richness decreased from rural to urban sites while bird abundance increased. Omnivores thrived in the city whereas insectivores and insectivore-frugivores were abundant in rural sites. Birds species richness was associated with plant species richness, while abundances of insectivores and insectivore-frugivores birds were related to shrub coverage and foliage height diversity. Our study highlighted that small cities can modify bird communities in the same way as large cities, thus policies for conservation of birds should be created to coincide with urbanizations. We recommend planting native species in all urban green spaces and informing citizens about the benefits of this action. If everybody collaborates, conservation of native birds in developing areas of Andean Patagonia will be possible.

Hitting the wall: Human sperm velocity recovery under ultra-confined conditions Bettera Marcat, Matías Alejandro; Gallea, Maria Noel; Miño, Gastón Leonardo; Cubilla, Marisa Angelica; Banchio, Adolfo Javier; Giojalas, Laura Cecilia; Marconi, Veronica Iris; Guidobaldi, Héctor Alejandro Infertility is a common medical condition encountered by health systems throughout the world. Despite the development of complex in vitro fertilization techniques, only one-third of these procedures are successful. New lab-on-a-chip systems that focus on spermatozoa selection require a better understanding of sperm behavior under ultra-confined conditions in order to improve outcomes. Experimental studies combined with models and simulations allow the evaluation of the efficiency of different lab-on-a-chip devices during the design process. In this work, we provide experimental evidence of the dynamics of sperm interacting with a lateral wall in a shallow chamber. We observe a decrease in average sperm velocity during initial wall interaction and partial recovery after the alignment of the trajectory of the cell. To describe this phenomenon, we propose a simple model for the sperm alignment process with a single free parameter. By incorporating experimental motility characterization into the model, we achieve an accurate description of the average velocity behavior of the sperm population close to walls. These results will contribute to the design of more efficient lab-on-a-chip devices for the treatment of human infertility.

Metodología para el análisis de las prácticas y políticas de ordenamiento territorial en América Latina. El caso de Argentina, Ecuador, México y Paraguay; Methodology for the analysis of land use practices and policies in Latin America. The case of Argentina, Ecuador, Mexico and Paraguay Villagómez, Martha; Cuesta, Rosa; Sili, Marcelo Enrique; Vieyra, Antonio El presente artículo es producto de un proyecto de investigación cuyo objetivo principal fue presentar, sobre la base de experiencias de casos multiescalares (nacional, regional, rural y metropolitano), una metodología que permita conocer el estado de situación de las iniciativas de ordenamiento territorial en cuatro países de América Latina, señalando los principales factores que limitan o inhiben su puesta en marcha y sus resultados, de manera tal que se puedan plantear algunas pistas y recomendaciones para la mejora de las políticas y las prácticas de ordenamiento territorial en toda la región.; This article is the product of a research project whose main objective was to present, on the basis of experiences of multiscale cases (national, regional, rural and city), a methodology that allows us to know the status of territorial planning initiatives in four Latin American countries, pointing out the main factors that limit or inhibit its implementation and its results, so that some clues and recommendations can be raised for the improvement of land use policies and practices throughout the region.The study was executed between 2017 and 2018, within the technical assistance projects (PAT) sponsored by the Pan American Institute of Geography and History (PAIGH) that is dependent on the Organization of American States (OAS) and had the participation of the Military Geographic Institute of Ecuador, the National Autonomous University of Mexico through the Environmental Geography Research Center (CIGA) of the Morelia Campus, the Development Research Center of Paraguay and the National University of the South through the ADETER Center (Territorial Action and Development) of Argentina. To this was added the support of numerous researchers from other universities and research centers in the countries involved. In this research framework, the strategy included field work through interviews with important actors and knowledgeable about the problem. In addition, secondary information was collected from the official sources of each nation, based on all these instruments several workshops and discussions were held that allowed to obtain several products.The result of the investigation recognized common problems around the territorial planning present in the four countries analyzed, and which are also manifested at all scalar levels; Subsequently, based on these common themes for all, based on the methodological instruments developed and the expert criteria of the participants, proposals were generated that provide practical ideas in order to improve territorial planning policies in Latin America.

Comparative analysis of the biosimilar and innovative G-CSF modulated pathways on umbilical cord blood–derived mononuclear cells Ávila Portillo, Luz Mabel; Aristizabal, F.; Perdomo, S.; Riveros, A.; Ospino, B.; Avila, J. P.; Butti, M.; Abba, Martín Carlos Biosimilars of granulocyte colony-stimulating factor (G-CSF) have been routinely introduced into clinical practice. However, not functional genomics characterization has been performed yet in comparison with the innovator G-CSF. This study aimed to evaluate the transcriptomic changes in an in vitro model of umbilical cord blood cells (UBC) exposed to G-CSF for the identification of their modulated pathways. Umbilical cord blood cells–derived mononuclear cells (MNCs) were treated with biosimilar and innovator G-CSF for further gene expression profiling analysis using a microarray-based platform. Comparative analysis of biosimilar and innovator G-CSF gene expression signatures allowed us to identify the most commonly modulated pathways by both drugs. In brief, we observed predominantly upmodulation of transcripts related to PI3K-Akt, NF-kappaB, and tumor necrosis factor (TNF) signaling pathways as well as transcripts related to negative regulation of apoptotic process among others. In addition, hematopoietic colony-forming cell assays corroborate the G-CSF phenotypic effects over UBC-derived MNCs. In conclusion, our study suggests that G-CSF impacts UBC-derived cells through the modulation of several signaling pathways associated with cell survival, migration, and proliferation. The concordance observed between biosimilar and innovator G-CSF emphasizes their similarity in regards to their specificity and biological responses.

Landscape and drainage evolution during the Cenozoic in the Salinas Grandes Basin, Andean Plateau of NW Argentina López Steinmetz, Romina Lucrecia; Avila, Pilar; Davila, Federico Miguel Endorheic basins are distinctive features of the modern Andean plateau. These basins record thick Neogene-to-Modern evaporite successions that are considered as the onset of internal drainage and aridity. Some isolated older (Paleogene) evaporites and intermontane depocenters have been also described across the Argentine Puna, suggesting that some degree of hydrological isolation would have pre-dated the main Miocene-Pliocene plateau uplift. Evaporites beds, however, are not conclusive evidence for endorheism, given that their formation depends not only on the tectonically-driven paleo-drainage, but also on other sensitive variables as climate, and salinity of the sources. Here, we discuss the paleo-drainage evolution across the eastern Puna plateau at 23°-24° S, combining landscape numerical modeling with seismic stratigraphy. Seismic observations suggest an intermontane configuration as early as the late Paleogene, and relief formation to the east and west basin margins. Using different combinations of precipitation rates, our landscape models allowed us to reproduce the modern elevations observed in the study region as well as published thermochronological data. Our results suggest that endorheism would have started in the Paleogene, and would have dominated most (>70%) of the Cenozoic basin history. Models show the recurrence of endorheism, interrupted by intermittent phases of drainage connectivity (exorheism) to the east (foreland) in the upper half Eocene and the early Miocene. According to these results, the formation of closed basins in the Puna region would have pre-dated the main Miocene-Pliocene uplift stage of the Andean plateau.

Exact and heuristic approaches for multi-objective garbage accumulation points location in real scenarios Rossit, Diego Gabriel; Toutouh, Jamal; Nesmachnow, Sergio Municipal solid waste management is a major challenge for nowadays urban societies, because it accounts for a large proportion of public budget and, when mishandled, it can lead to environmental and social problems. This work focuses on the problem of locating waste bins in an urban area, which is considered to have a strong influence in the overall efficiency of the reverse logistic chain. This article contributes with an exact multiobjective approach to solve the waste bin location in which the optimization criteria that are considered are: the accessibility to the system (as quality of service measure), the investment cost, and the required frequency of waste removal from the bins (as a proxy of the posterior routing costs). In this approach, different methods to obtain the objectives ideal and nadir values over the Pareto front are proposed and compared. Then, a family of heuristic methods based on the PageRank algorithm is proposed which aims to optimize the accessibility to the system, the amount of collected waste and the installation cost. The experimental evaluation was performed on real-world scenarios of the cities of Montevideo, Uruguay, and Bahía Blanca, Argentina. The obtained results show the competitiveness of the proposed approaches for constructing a set of candidate solutions that considers the different trade-offs between the optimization criteria.