Mitochondrial calcium handling in normotensive and spontaneously hypertensive rats: correlation with systolic blood pressure levels Ciocci Pardo, Alejandro; Rinaldi, Gustavo Juan; Mosca, Susana Maria The aim was to study the mitochondrial Ca2+ handling of mitochondria isolated from normotensive Wistar Kyoto(WKY) and spontaneously hypertensive rats (SHR) hearts and to establish a possible correlation with systolic blood pressure (SBP). Mitochondrial swelling after Ca2+ addition, Ca2+-retention capacity (CRC) by calcium green method, and membrane potential (ΔΨm) were assessed. SBP was 124 ± 1 (WKY) and 235 ± 6 mm Hg(SHR). CRC, Ca2+ response and ΔΨm were lower in SHR than WKY mitochondria. The conclusion is: the more depolarized state of SHR than WKY mitochondria results in an abnormal Ca2+ handling and this event is closelyassociated with the SBP.

Más allá del principio contributivo: cambios y continuidades en la política social argentina, 2003-2011 Alonso, Guillermo Victor; Di Costa Tita, Valeria Noemi El objetivo de este artículo es presentar las transformaciones producidas en las políticas sociales argentinas durante el periodo del gobierno de Néstor Kirchner (2003-2007) y del primer mandato de Cristina Fernández de Kirchner (2007-2011). No haremos una enumeración de políticas y medidas de modo exhaustivo, pero la descripción y análisis permitirá mostrar, al considerar los programas y sistemas de cobertura poblacional más extendida, la corriente principal de la política social argentina durante estos años. En especial, analizaremos los cambios producidos en el sistema de seguridad social, y mostraremos que la estrategia que inicialmente pareció encaminada a simplemente restaurar la centralidad del seguro social contributivo sobre bases más amplias, innovó planteando rupturas significativas con la lógica del principio contributivo como ar- ticulador del sistema de protección social.

Excitation functions for the production of radionuclides by neutron-induced reactions on C, O, Mg, Al, Si, Fe, Co, Ni, Cu, Ag, Te, Pb, and U up to 180 MeV Michel, R.; Hansmann, David; Neumann, S.; Glasser, W.; Schuhmacher, H.; Dangendorf, V.; Nolte, R.; Herpers, U.; Smirnov, A.N.; Ryzhov, I.V.; Prokofiev, A.V.; Malmborg, P.; Kollár, D.; Meulders, J.-P. Irradiation experiments with well-characterized, quasi mono-energetic neutrons of energies between 32.7 MeV and 175.4 MeV were performed at UCL/Louvain-la-Neuve and TSL/Uppsala. The abundances of relatively short-lived residual radionuclides from 13 different target elements were determined by γ-spectrometry. More than 100 excitation functions of neutron-induced reactions were unfolded based on the neutron spectra and the radionuclide abundances with the aid of additional information that was provided by "guess" excitation functions calculated by the TALYS 1.0 code. The results are compared with the sparse existing data from other authors. The new excitation functions were validated by calculation of and comparison with experimental thick-target production rates. Consistency with neutron excitation functions up to 1.6 GeV, which were derived earlier by unfolding the thick-target production rates, was so demonstrated.

Insights into the mechanism of the reaction between hydrogen sulfide and peroxynitrite Cuevasanta, Ernesto; Zeida Camacho, Ari Fernando; Carballal, Sebastián; Wedmann, Rudolf; Morzan, Uriel N.; Trujillo, Madia; Radi, Rafael; Estrin, Dario Ariel; Filipovic, Milos R.; Alvarez, Beatriz Hydrogen sulfide and peroxynitrite are endogenously generated molecules that participate in biologically relevant pathways. A revision of the kinetic features of the reaction between peroxynitrite and hydrogen sulfide revealed a complex process. The rate constant of peroxynitrite decay, (6.65 ± 0.08) × 103 M-1 s-1 in 0.05 M sodium phosphate buffer (pH 7.4, 37 °C), was affected by the concentration of buffer. Theoretical modeling suggested that, as in the case of thiols, the reaction is initiated by the nucleophilic attack of HS- on the peroxide group of ONOOH by a typical bimolecular nucleophilic substitution, yielding HSOH and NO2 -. In contrast to thiols, the reaction then proceeds to the formation of distinct products that absorb near 408 nm. Experiments in the presence of scavengers and carbon dioxide showed that free radicals are unlikely to be involved in the formation of these products. The results are consistent with product formation involving the reactive intermediate HSSH and its fast reaction with a second peroxynitrite molecule. Mass spectrometry and UV-Vis absorption spectra predictions suggest that at least one of the products is HSNO2 or its isomer HSONO.

Dendrogeomorphic reconstruction of flash floods in the Patagonian Andes Casteller, Alejandro; Stoffel, Markus; Crespo, Sebastián Andrés; Villalba, Ricardo; Corona, Christophe; Bianchi, Emilio Flash floods represent a significant natural hazard in small mountainous catchments of the Patagonian Andes and have repeatedly caused loss to life and infrastructure. At the same time, however, documentary records of past events remain fairly scarce and highly fragmentary in most cases. In this study, we therefore reconstruct the spatiotemporal patterns of past flash flood activity along the Los Cipreses torrent (Neuquén, Argentina) using dendrogeomorphic methods. Based on samples from Austrocedrus chilensis, Pseudotsuga menziesii, and Nothofagus dombeyi, we document 21 flash flood events covering the period A.D. 1890-2009 and reconstruct mean recurrence intervals of events at the level of individual trees being impacted, which varies from 4 to 93. years. Results show that trees tend to be older (younger) in sectors of the torrent with gentler (steeper) slope gradients. Potential triggers of flash floods were analyzed using daily temperature and precipitation data from a nearby weather station. Weather conditions leading to flash floods are abundant precipitations during one to three consecutive days, combined with temperatures above the rain/snow threshold (2. °C) in the whole watershed.

La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment Moreira, Pilar; Fernandez, Raul Roberto The La Josefina Jurassic epithermal Au-Ag deposit located in Patagonia, Argentina, developed in an extensional setting of a back-arc environment, associated with a widespread Middle-Late Jurassic calc-alkaline volcanism. Block faulting has juxtaposed shallow level features evidenced by hot spring manifestations, hydrothermal eruption breccias and Au-rich veins, which suggest that mineralization in these veins, could extend far below the depths already tested by core drilling. Veins are filled by quartz, chalcedony, opal and minor adularia and barite with massive, comb, cockade, colloform-crustiform bandings and lattice-bladed textures. Ore minerals include electrum, Ag-rich sulfosalts (freibergite), pyrite, galena, sphalerite, chalcopyrite and specular hematite with minor arsenopyrite, marcasite, tetrahedrite and bornite. Four mineralizing stages have been identified, the first two (S1 and S2) are Au and Ag-rich, with temperatures ranging from 225 to 290° and salinities from up to 15 wt.% in S1 decreasing to ~1 wt.% NaCl in S2. The third stage (S3) displays higher base metal contents at lower temperatures (~200 °C). Finally, the last stage (S4) is barren with temperatures lower than 100 °C. Veins are surrounded by a proximal alteration halo of quartz + pyrite ± adularia ± illite followed outwards by illite/smectite interstratified clays and smectites (with less chlorite) to a propylitic zone. Stable isotope values calculated for the fluids show a mostly meteoric origin for mineralization fluids. Such distinct features place the La Josefina deposits in a hot spring environment with evidences of being formed at a proximal position of the Jurassic paleosurface and paleowater level.

Temperature evolution of the effective magnetic anisotropy in the MnCr2O4 spinel Tobia, Dina; Milano, Julian; Causa, Maria Teresa Beatriz; Winkler, Elin Lilian In this work, we present a study of the low temperature magnetic phases of polycrystalline MnCr2O4 spinel through dc magnetization and ferromagnetic resonance spectroscopy (FMR). Through these experiments, we determined the main characteristic temperatures: TC ∼ 41K and TH ∼ 18K corresponding, respectively, to the ferrimagnetic order and to the low temperature helicoidal transitions. The temperature evolution of the system is described by a phenomenological approach that considers the different terms that contribute to the free energy density. Below the Curie temperature, the FMR spectra were modeled by a cubic magnetocrystalline anisotropy to the second order, with K1 and K2 anisotropy constants that define the easy magnetization axis along the 〈110〉 direction. At lower temperatures, the formation of a helicoidal phase was considered by including uniaxial anisotropy axis along the [110] propagation direction of the spiral arrange, with a Ku anisotropy constant. The values obtained from the fittings at 5K are K1 = -2.3 × 104 erg cm-3, K2 = 6.4 × 104 erg cm-3 and Ku = 7.5 × 104 erg cm-3.

Unplanned pregnancies and reproductive health among women with bipolar disorder Marengo, Eliana; Martino, Diego Javier; Igoa, Ana; Scápola, María; Fassi, Guillermo; Baamonde, Mariana Urtueta; Strejilevich, Sergio Abstract Background The aim of this study was to investigate reproductive health and level of planning of pregnancies among women with bipolar disorder (BDW). Methods 63 euthymic women, with bipolar disorder type I, II or not otherwise specified diagnosis, were included and were matched with a control group of 63 healthy women. Demographic and clinical data, structured reproductive health measures and planning level of pregnancies were obtained and compared between groups. Results Lower level of planning of pregnancies and higher frequency of unplanned pregnancies were found among BDW. Women with bipolar disorder reported history of voluntary interruption of pregnancies more frequent than women from control group. Current reproductive health care showed no differences between groups. Limitations Data based on self-report of participants and retrospective nature of some collected measures may be affected by information bias. The pregnancy planning measure has not been validated in this population before. Demographic and clinical characteristics of the sample study limit generalization of these findings. Conclusions Adverse reproductive events, as unplanned pregnancies and elective interruption of pregnancies, may be more frequent among BDW. Clinician must be aware of the reproductive health during treatment of young BDW and take measures to improve better family planning access.

TacoFlow: optimizing SAT program verification using dataflow analysis Cuervo Parrino, Bruno; Galeotti, Juan Pablo; Garbervetsky, Diego David; Frias, Marcelo Fabian In previous work, we presented TACO, a tool for efficient bounded verification. TACO translates programs annotated with contracts to a SAT problem which is then solved resorting to off-the-shelf SAT-solvers. TACO may deem propositional variables used in the description of a program initial states as being unnecessary. Since the worst-case complexity of SAT (a known NP problem) depends on the number of variables, most times this allows us to obtain significant speed ups. In this article, we present TacoFlow, an improvement over TACO that uses dataflow analysis in order to also discard propositional variables that describe intermediate program states. We present an extensive empirical evaluation that considers the effect of removing those variables at different levels of abstraction, and a discussion on the benefits of the proposed approach.

Familial hemiplegic migraine type-1 mutated cav2.1 calcium channels alter inhibitory and excitatory synaptic transmission in the lateral superior olive of mice González Inchauspe, Carlota María Fabiola; Pilati, Nadia; Di Guilmi, Mariano Nicolás; Urbano Suarez, Francisco Jose; Ferrari, Michel D.; Maagdenberg, Arn M. J. M. van den; Forsythe, Ian D.; Uchitel, Osvaldo Daniel CaV2.1 Ca2+ channels play a key role in triggering neurotransmitter release and mediating synaptic transmission. Familial hemiplegic migraine type-1 (FHM-1) is caused by missense mutations in the CACNA1A gene that encodes the α1A pore-forming subunit of CaV2.1 Ca2+ channels. We used knock-in (KI) transgenic mice harbouring the pathogenic FHM-1 mutation R192Q to study inhibitory and excitatory neurotransmission in the principle neurons of the lateral superior olive (LSO) in the auditory brainstem. We tested if the R192Q FHM-1 mutation differentially affects excitatory and inhibitory synaptic transmission, disturbing the normal balance between excitation and inhibition in this nucleus. Whole cell patch-clamp was used to measure neurotransmitter elicited excitatory (EPSCs) and inhibitory (IPSCs) postsynaptic currents in wild-type (WT) and R192Q KI mice. Our results showed that the FHM-1 mutation in CaV2.1 channels has multiple effects. Evoked EPSC amplitudes were smaller whereas evoked and miniature IPSC amplitudes were larger in R192Q KI compared to WT mice. In addition, in R192Q KI mice, the release probability was enhanced compared to WT, at both inhibitory (0.53±0.02 vs. 0.44±0.01, P=2.10-5, Student's t-test) and excitatory synapses (0.60±0.03 vs. 0.45±0.02, P=4 10-6, Student's t-test). Vesicle pool size was diminished in R192Q KI mice compared to WT mice (68±6 vs 91±7, P=0.008, inhibitory; 104±13 vs 335±30, P=10-6, excitatory, Student's t-test). R192Q KI mice present enhanced short-term plasticity. Repetitive stimulation of the afferent axons caused short-term depression (STD) of E/IPSCs that recovered significantly faster in R192Q KI mice compared to WT. This supports the hypothesis of a gain-of-function of the CaV2.1 channels in R192Q KI mice, which alters the balance of excitatory/inhibitory inputs and could also have implications in the altered cortical excitability responsible for FHM pathology.

Detection of thiourea from electrorefining baths using silver nanoparticles-based sensors Pedre, Ignacio; Battaglini, Fernando; Delgado, Gladis Judith Labrada; Sánchez Loredo, María Guadalupe; González, Graciela Alicia A novel and easy-to-use colorimetric thiourea (TU) sensor based on immobilized polyvinylpyrrolidone-stabilized silver nanoparticles (PVP-AgNPs) is reported. The new sensor is aimed for its direct application in copper electrorefinery baths. Quantitative analysis was carried out by adding different thiourea amounts into a synthetic bath and monitoring the absorption changes of the surface plasmon resonance band (SPRB) by UV-Vis spectrophotometry. A linear correlation between the absorbance change and thiourea concentration was obtained, ranging from 0.125 mg/L to 1 mg/L. Our technique has the advantage of working in acidic and high ionic concentrated solutions as those used in electrorefinery baths. The influence of the nanoparticles synthesis conditions on the thiourea sensing was analyzed; particularly, the effect of using different silver concentrations and the same amount of borohydride ions as reducing agent ([Ag+]/[BH4 -] ratios of 2:1, 8:1, 10:1 and 20:1 during the synthesis). The proposed system provides a simple, economical, easy-to-handle and rapid measurement tool for monitoring hydrometallurgical processes for optimizing the reconditioning of thiourea solutions, reducing its environmental impact.

σ-Ideals in distributive pseudocomplemented residuated lattices Celani, Sergio Arturo In this paper we shall introduce the notion of σ- ideals in the variety of pseudocomplemented residuated lattices.We shall also give some characterizations of the stonean pseudocomplemented residuated lattices.

Feasibility study of a hybrid subcritical fission system driven by Plasma-Focus fusion neutrons Clausse, Alejandro; Soto, Leopoldo; Friedli, Carlos; Altamirano, Luis A feasibility analysis of a hybrid fusion–fission system consisting of a two-stage spherical subcritical cascade driven by a Plasma Focus device is presented. The analysis is based on the one-group neutron diffusion equation, which was appropriately cast to assess the neutronic amplification of a spherical configuration. A design chart was produced to estimate the optimum dimensions of the fissile shells required to achieve different levels of neutron amplification. It is found that cascades driven by Plasma Focus of tens of kJ are feasible. The results were corroborated by means of Monte Carlo calculations.

Sedimentología e Icnología de deltas fluvio-dominados afectados por descargas hiperpícnicas de la Formación Lajas (Jurásico Medio), Cuenca Neuquina, Argentina Canale, Nerina; Ponce, Juan Jose; Carmona, Noelia Beatriz; Drittanti, Daniel; Olivera, Daniela Elizabeth; Martinez, Marcelo Adrian; Bournod, Constanza Naimé En las áreas de Portada Covunco y Sierra de la Vaca Muerta, la Formación Lajas representa una sucesión deltaica fluvio-dominada integrada por depósitos de prodelta y frente deltaico, afectados por descargas hiperpícnicas y reelaborados por acción de oleaje (normal y de tormenta). Los depósitos de prodelta muestran una marcada geometría tabular con alternancia entre fangolitas y areniscas finas con abundante contenido de materia orgánica y desarrollo de una icnofacies de Cruziana empobrecida. Los depósitos de frente deltaico, integrados por fangolitas, areniscas finas a gruesas y conglomerados finos, presentan cuerpos de geometría tabular con desarrollo de las icnofacies de Skolithos y Glossifungites, esta última relacionada a la avulsión de lóbulos deltaicos. La progradación normal del sistema deltaico muestra intervalos estratigráficos integrados por cuerpos lenticulares y tabulares de espesor variable asignados a canales y lóbulos hiperpícnicos. Internamente estos depósitos presentan un pasaje transicional y recurrente entre diferentes estructuras sedimentarias con marcadas variaciones texturales, múltiples superficies de reactivación interna, y abundante contenido de materia orgánica. Los sistemas de canales hiperpícnicos muestran dimensiones y estilos de relleno diferentes. Al pie de las zonas de mayor gradiente, las descargas hiperpícnicas generaron canales mayores con relleno agradacional, mientras que en posiciones de menor gradiente del sistema, se desarrollaron canales de alta sinuosidad. En las zonas donde el flujo hiperpícnico perdió confinamiento se produjo la acumulación de sistemas de lóbulos hiperpícnicos. La presencia de niveles de conglomerados afectados por acción de oleaje coronando los arreglos, marcan los planos de pausa en la sedimentación, en los cuales se desarrollaron ventanas de colonización para el establecimiento de la fauna bentónica.; There are few recognized examples of fluvial-dominated deltaic systems affected by hyperpycnal discharges. The development of predictive models in those systems are essential to understand the distribution of sedimentary facies and for determining the location of the main sandy bodies, which constitute the potential hidrocarbon reservoirs. In Portada Covunco and Sierra de la Vaca Muerta areas (Neuquén, Argentina), the Lajas Formation constitutes an excellent example of a deltaic fluvio-dominated succession consisting of prodelta and deltaic front deposits, affected by hyperpycnal discharges and reworked by wave action (storm and normal wave action). Prodelta deposits show a strongly tabular geometry alternating between mudstones and fine sandstones with abundant organic matter and development of an impoverished Cruziana ichnofacies. Deltaic-front deposits are integrated by mudstones, fine to coarse sandstones and fine conglomerates showing tabular geometries and development of the Skolithos and Glossifungites ichnofacies, the later related to deltaic lobe avulsión. Normal progradation of this deltaic system shows stratigraphic intervals consisting of tabular and lenticular bodies of variable thicknesses assigned to hyperpycnal-channel and lobe systems. Internally, these deposits show transitional and recurrent passages between different sedimentary structures with marked textural variations, multiple internal reactivation surfaces and abundant organic matter content. Hyperpycnal channels systems have different dimensions and fill patterns. At the foot of the areas with the greatest gradients, hyperpycnal discharges produced mayor channels with aggradational fill, whereas in areas with lower gradients, high sinuosity channels developed. Hyperpycnal lobes were accumulated in areas where hyperpycnal flows lost confinement. The presence of conglomeratic levels affected by wave action on top of the lobe deposits indicates pauses in sedimentation during which colonization windows could develope, allowing the establishment of the benthic fauna.

The composition of arbuscular mycorrhizal fungal communities in the roots of a ruderal forb is not related to the forest fragmentation process Grilli, Gabriel; Urcelay, Roberto Carlos; Galetto, Leonardo; Davison, John; Vasar, Martii; Saks, Úlle; Jairus, Teele; Ópik, Maarja Land-use changes and forest fragmentation have strong impact on biodiversity. However, little is known about the influence of new landscape configurations on arbuscular mycorrhizal fungal (AMF) community composition. We used 454 pyrosequencing to assess AMF diversity in plant roots from a fragmented forest. We detected 59 virtual taxa (VT; phylogenetically defined operational taxonomic units) of AMF – including 10 new VT – in the roots of Euphorbia acerensis. AMF communities were mainly composed of members of family Glomeraceae and were similar throughout the fragmented landscape, despite variation in forest fragment size (i.e. small, medium and large) and isolation (i.e. varying pairwise distances). AMF communities in forest fragments were phylogenetically clustered compared with the global, but not regional and local AMF taxon pools. This indicates that non-random community assembly processes possibly related to dispersal limitation at a large scale, rather than habitat filtering or biotic interactions, may be important in structuring the AMF communities. In this system, forest fragmentation did not appear to influence AMF community composition in the roots of the ruderal plant. Whether this is true for AMF communities in soil and the roots of other ecological groups of host plants or in other habitats deserves further study.

La pesca marítima en la Argentina (1989-2013): un caso de (neo)extractivismo y acumulación por desposesión Gómez Lende, Sebastián Orden global y acumulación por desposesión son, en la actualidad, fenómenos y procesos íntimamente conectados: transportada a los lugares por las empresas globales, y encarnada por la lógica del mercado mundial, esa racionalidad hegemónica opera como un elemento de perturbación y desestructuración allí donde se instala. Los usos extractivos del territorio, en tanto que protagonistas privilegiados de la actual fase u oleada de acumulación por desposesión, instauran un nuevo orden de prioridades funcional a los intereses del capital globalizado, el cual lleva la lógica de "economía de enclave" a su más alto nivel y le arrebata a las sociedades nacionales sus recursos más valiosos. A la luz de ese sistema de ideas, este trabajo estudia el proceso de reestructuración de la pesca marítima en la Argentina durante el período 1989-2013, analizando para ello la reorganización de la legislación que rige al sector, el grado de concentración del capital, el nivel de extranjerización de la flota, el destino de la producción y los conflictos suscitados entre los distintos agentes intervinientes en la actividad, para dar cuenta de sus graves implicancias respecto de la capacidad biológica de renovación del recurso, su escasez en el mercado interno y las condiciones laborales del sector.

Systematic revision of Late Triassic marine gastropods from Central Perú: considerations on the Late Triassic/Early Jurassic faunal turnover; Revisión sistemática de los gastrópodos marinos del Triásico superior de Perú Central: consideraciones sobre el recambio faunístico en límite Triásico tardío/Jurásico temprano Ferrari, Silvia Mariel The Late Triassic/Early Jurassic boundary is marked by a mass extinction event which had an important effect on the marine benthic communities on a global scale. In the Andean region of South America, however, the impact of this phenomenon on the earliest Mesozoic marine invertebrate associations has not been evaluated thus far. The present contribution is a systematic revision of the Late Triassic marine benthic gastropod faunas from the Pucará Group of Central Perú, giving a detailed characterization of 18 species and an updated systematic assigment of representatives of the genera Chartroniella, Phymatifer, Ptychomphalina, Paracerithium, Rhabdocolpus and Omphaloptycha. This research includes a comparison of the Peruvian fauna with their related counterparts from the Early Jurassic of Argentina and the Early/Middle Jurassic of New Zealand. This approach attempts to interpret the Late Triassic/Early Jurassic faunal turnover after the end Triassic crisis and establishes a palaeobiogeographical scheme for the gastropod faunal exchange in the Southern Hemisphere across the palaeo-Pacific seaway during the Late Triassic/Early Jurassic.; El límite Triásico tardío/Jurásico temprano está marcado por un evento de extinción en masa que tuvo un efecto importante en las comunidades marinas bentónicas a escala global. Sin embargo, el impacto de dicho fenómeno sobre las asociaciones de invertebrados marinos del Mesozoico temprano en la región andina de América del Sur no ha sido evaluado hasta el momento. La presente contribución es una revisión sistemática de la fauna de gastrópodos marinos bentónicos procedentes del grupo Pucará en Perú Central, en la que se da una caracterización morfológica detallada de 18 especies y una asignación sistemática actualizada de representantes de los géneros Chartroniella, Phymatifer, Ptychomphalina, Paracerithium, Rhabdocolpus y Omphaloptycha. Este trabajo incluye una comparación de las faunas peruanas con faunas similares correspondientes al Jurásico temprano de Argentina y al Jurásico temprano/medio de Nueva Zelanda. Asimismo, el presente enfoque apunta a interpretar, el recambio faunístico que tuvo lugar en el límite Triásico tardío/Jurásico temprano después de la gran crisis de finales del Triásico, y a establecer un esquema paleobiogeográfico para los gastrópodos en el Hemisferio Sur a lo largo del corredor Paleo-Pacífico.

Comparación morfométrica entre lagunas de la planicie aluvial del río Paraná Medio y La Lomada Norte (Corrientes, Argentina); Comparação morfométrica entre lagunas da planície aluvial do médio rio Paraná e a Lomada Norte (Corrientes, Argentina); Morphometric comparison of lakes on the alluvial plain of the Paraná Medio River and the Lomada Norte (Corrientes, Argentina) Contreras, Félix Ignacio; Paira, Aldo Raul El desarrollo de la línea de costa (DL) es una medida morfométrica que permite conocer cuantitativamente la forma de la cubeta. El objetivo de este trabajo es comparar el DL de un grupo de lagunas que, aunque se encuentran en una misma región, son geológica y geomorfológicamente distintas. Para ello, se midieron 925 lagunas,correspondientes a la totalidad de cuerpos leníticos de la Lomada Norte, y 1.500 lagunas de la llanura aluvial del río Paraná Medio. Los resultados demostraron que en las primeras existe un predominio de lagunas circulares que evolucionan a formas más complejas, mientras que en las segundas, en su mayoría, son lagunas de forma alargada evolucionando a ovales o circulares.; O desenvolvimento da linha de costa (DL ) é uma medida morfométrica que permite conhecer quantitativamente a forma da bacia. O objetivo deste trabalho é comparar o DL de um grupo de lagunas que, embora se encontrem numa mesma região, são geológica e geomorfologicamente diferentes. Para isso, mediram-se 925 lagunas, correspondentes à totalidade de corpos leníticos da Lomada Norte, e 1.500 lagunas da planície aluvial do rio Paraná Médio. Os resultados demonstraram que, nas primeiras, existe um predomínio de lagunas circulares que evoluem a formas mais complexas, enquanto nas segundas, em sua maioria, são lagunas de forma alongada, que evoluem a ovais ou circulares.; Shoreline development (DL ) is a morphometric measure that provides quantitative knowledge of the shape of a basin. The objective of this project was to compare the DL of a group of shallow lakes, which despite being located in the same region, present geological and geomorphological differences. To that effect, we measured 925 shallow lakes corresponding to the totality of lenticular (lentiform) bodies of the Lomada Norte and 1500 fluvial lakes of the alluvial plain of the Parana Medio river. The results showed that circular lakes evolving into more complex forms predominate in the former, while in the latter, the majority are elongated lakes evolving into oval or circular shapes.

Separation versus diffusion in a two species system De Masi, Anna; Ferrari, Pablo Augusto We consider a finite number of particles that move in ZZ as independent random walks. The particles are of two species that we call aa and bb. The rightmost aa-particle becomes a bb-particle at constant rate, while the leftmost bb-particle becomes aa-particle at the same rate, independently. We prove that in the hydrodynamic limit the evolution is described by a nonlinear system of two PDE’s with free boundaries.

Flexible-structured systems made of ceramic fibers containing Pt-NaY zeolite used as CO oxidation catalysts Cecchini, Juan Pablo; Banus, Ezequiel David; Leonardi, Sabrina Antonela; Zanuttini, Miguel Angel Mario; Ulla, Maria Alicia del H.; Milt, Viviana Guadalupe Catalytic ceramic papers were developed by incorporating Pt-NaY zeolite to ceramic papers. The necessary mechanical strength was enhanced by the addition of natural borate compounds, which confer elasticity and resistance similar to those obtained using colloidal suspensions, which are the most commonly used binders. Pt-NaY zeolite was incorporated into ceramic papers either during the papermaking process or by spraying a zeolitic suspension on ceramic papers. The partial encapsulation of the faujasite by the sintering of the borate compound during the calcination step made catalytic ceramic papers less active toward the CO oxidation reaction than the corresponding traditional systems (Pt-NaY zeolite coated onto cordierite monoliths or the powder Pt-NaY faujasite). Light-off curves indicated that the activity of Pt-NaY zeolite was preserved when incorporating the zeolitic component by spray, in which case the CO oxidation reaction ran away at ca. 130 °C, and the total CO conversion was achieved at 150 °C, maintaining 100 % CO conversion for more than 90 h.