Physicochemical and structural properties of amaranth protein isolates treated with high pressure Condes, María Cecilia; Speroni Aguirre, Francisco José; Mauri, Adriana Noemi; Añon, Maria Cristina The effects of high pressure (HP) (200, 400 and 600 MPa) on physicochemical and structural properties of amaranth proteins treated at different protein concentrations (1, 5 and 10% w/v) were studied. HP provoked denaturation of amaranth proteins which were very sensitive to HP treatment, achieving almost complete denaturation (93%) at 400 MPa. After HP, the resistant structures from glutenins, globulin-11S and globulin-P exhibited an increased thermal stability while those from albumins and globulin-7S exhibited a decrease of thermal stability. Increasing intensities of HP treatments provoked the disappearance of electrophoretic bands with molecular mass higher than 45 kDa, together with changes in the polypeptides fractions of low molecular weight. HP treatments induced the formation of insoluble aggregates and the dissociation of soluble aggregates. Protein concentration modulated the effects of HP on amaranth proteins. These modified proteins could present improved functional properties.

Galaxy triplets in Sloan Digital Sky Survey Data Release 7 - I. Catalogue O'Mill, Ana Laura; Duplancic Videla, Maria Fernanda; Garcia Lambas, Diego Rodolfo; Valotto, Carlos Alberto; Sodré Laerte, Jr We present a new catalogue of galaxy triplets derived from the Sloan Digital Sky Survey Data Release 7. The identification of systems was performed considering galaxies brighter than M_r=-20.5 and imposing constraints over the projected distances, radial velocity differences of neighbouring galaxies and isolation. To improve the identification of triplets we employed a data pixelization scheme, which allows to handle large amounts of data as in the SDSS photometric survey. Using spectroscopic and photometric data in the redshift range 0.01

Microbivalves from the Monte Leon Formation (Early Miocene), Patagonia, Argentina Griffin, Miguel; Pastorino, Roberto Santiago Guido Three new species (Mysella donaciformis n. sp., Cosa helianthea n. sp., and Lissarca saraballentae n. sp.) of small bivalves are described from early Miocene rocks in southern Patagonia. The outcrops lie along the coast of the province of Santa Cruz, within the boundaries of the Monte León National Park. The fossil-rich rocks exposed there at the base of the coastal cliff are included in the Punta Entrada Member of the Monte León Formation. This stratigraphic unit has been dated as early Miocene. It was probably deposited in a tidally-influenced near-shore and fully marine environment. The affinities of these small mollusks lie with taxa known to occur in other areas of the Southern Ocean, such as Antarctica, Australia, and New Zealand. The dispersal of these mollusks across vast expanses of water by means of rafting on drifting kelp is discussed.

Invasive non-native species of fish in Upper Paraná river Basin, Brazil: variations of caloric content in Cichla kelberi Espinola, Luis Guillermo; Júlio Junior, H. F; Benedito, E The allocation of assimilated energy may be influenced by seasonal changes, growth, and reproductive cycle of fish, food consumption and environmental conditions. The objective of this research was to evaluate the energetic variations of Cichla kelberi in the upper Paraná River floodplain, analyzing the caloric content in muscles, gonadosomatic index (GSI), and the condition factor between assessed systems, sex, and stage of gonadal maturation. The results obtained in the present study permit assuring that this is a species that efficiently converts the resources of the environment into energy. Although presenting higher condition factor in the environment where there is a greater ease in getting food (Paraná subsystem), the energy identified in the muscles was the same in both subsystems. During the process of gonadal maturation there is optimization in energy accumulation in the muscles of females, before and after reproductive period, and somatic growth occurs significantly when the individual is not reproducing. Further detailed studies on ecological mechanisms influencing the success of the species, as the presence of competitors and preference for native preys, are needed to implement effective management measures aimed at preventing that the species proliferation in the environment is even more damaging to local biodiversity.

Electrocatalysis: Fundamentals and Applications Zinola, Carlos F.; Martins, María Elisa; Pastor Tejera, E.; Pimenta Neves, Newton Electrocatalysis is a special field in Electrochemistry that hasgained a special growth after the late eighties due to theapplication of new hybrid techniques. However, most of theapplications have run for academic purposes but not fortechnical uses in the industry. Nowadays, the application ofnew concepts of electrocatalysis for industrial electrochemi-cal processes has appeared as a necessity and not only attract-ing attention for chemists but for engineers. Therefore,industrial electrocatalytic processes have only been presentedin the literature from the chemical engineering point of viewwith few further electrochemical explanations and mainlyduring the late seventies. The design and preparation of anelectrocatalyst (electrodes for technological uses) are basedon new concepts such as a controlled surface roughness,atomic topographic profiles, defined catalytic centre sites,atomic rearrangements, and phase transitions in the courseof the electrochemical reactions.

Importancia del autoabastecimiento energético: Impactos directos e indirectos sobre el crecimiento Recalde, Marina Yesica Este trabajo presenta un abordaje teórico de las implicancias directas, dados los límites biofísicos de la economía, e indirectas, por intermedio del impacto en la balanza comercial, de la falta de abastecimiento local. Como caso de estudio se analiza la situación actual del sistema energético argentino, y la existencia de ambas limitaciones a raíz de la caída del grado de autoabastecimiento energético y las crecientes demandas de importación de recursos energéticos. Los resultados del análisis muestran que la falta de abastecimiento local requerirá de importaciones crecientes de energía para sustentar el crecimiento económico, particularmente en el caso de países en desarrollo como Argentina. Esta situación ejerce una presión sobre la balanza de pagos, tal como lo predice la Ley de Thirwall, aún más importante atendiendo a la estructura de las importaciones y exportaciones locales. Se desprende de las conclusiones la importancia de la política energética tendiente al autoabastecimiento nacional.

Association between BoLA-DRB3 and somatic cell count in Holstein cattle from Argentina Baltian, Laura Rosana; Ripoli, María Verónica; Sanfilippo, S.; Takeshima, S. N.; Aida, Y.; Giovambattista, Guillermo Different studies have proved that the resistance/susceptibility to mastitis is genetically determined. The major histocompatibility complex in cows is known as bovine lymphocyte antigen (BoLA). Genes from the BoLA have been associated with the occurrence of infectious diseases such as mastitis and leukosis, especially the BoLA-DRB gene. The object of the present study was to detect associations between BoLA-DRB3 alleles and somatic cell count (SCC), as an indicator of resistance/ susceptibility to mastitis in Holstein cattle (N = 123) from La Pampa, Argentina. Fisher's exact test and Woolf- Haldane odds ratio were applied to study the association between SCC and BoLA-DRB3 allele frequencies. Significant association was noted between BoLA-DRB3.2*23 and *27 alleles (p <0.05) and protective or susceptibility effects, respectively. In addition, alleles BoLA-DRB3.2*20 and *25 exhibit suggestive association with high SCC (p < 0.1). These results were partially in agreement with data reported from Japanese Holstein cattle, but differed from those published by other authors. A possible explanation for the contrasting results could be that the mastitis is a multifactor disease caused by different pathogens. Moreover, most of the studies were carried out using PCR-RFLP method, which has less resolution than PCR-SBT because PCR-RFLP defined alleles included more than one sequenced alleles.

CD137 differentially regulates innate and adaptive immunity against Mycobacterium tuberculosis Fernández Do Porto, Darío Augusto; Jurado, Javier Oscar; Pasquinelli, Virginia; Alvarez, Ivana Belén; Aspera, Romina Haydeé; Musella, Rosa María; García, Verónica Edith Protective immunity against Mycobacterium tuberculosis is primarily mediated by the interaction of antigen-specific T cells and antigen presenting cells, which often depends on the interplay of cytokines produced by these cells. Costimulatory signals represent a complex network of receptor-ligand interactions that qualitatively and quantitatively influence immune responses. Thus, here we investigated the function of CD137 and CD137L, molecules known to have a central role in immune regulation, during human tuberculosis (TB). We demonstrated that M. tuberculosis antigen stimulation increased both CD137 and CD137L expression on monocytes and NK cells from TB patients and healthy donors, but only up-regulated CD137 on T lymphocytes. Blockage of the CD137 pathway enhanced the levels of interferon (IFN)-γ and tumor necrosis factor (TNF)-α produced by monocytes and NK against M. tuberculosis. In contrast, CD137 blockage significantly decreased the specific degranulation of CD8(+) T cells and the percentage of specific IFN-γ and TNF-α producing lymphocytes against the pathogen. Furthermore, inhibition of the CD137 pathway markedly increased T-cell apoptosis. Taken together, our results demonstrate that CD137:CD137L interactions regulate the innate and adaptive immune response of the host against M. tuberculosis.

Imaging nanometer-sized α-synuclein aggregates by superresolution fluorescence localization microscopy Roberti, Maria Julia; Fölling, Jonas; Celej, Maria Soledad; Bossi, Mariano Luis; Jovin, Thomas M.; Jares, Elizabeth Andrea The morphological features of alpha-synuclein (AS) amyloid aggregation in vitro and in cells were elucidated at the nanoscale by far-field subdiffraction fluorescence localization microscopy. Labeling AS with rhodamine spiroamide probes allowed us to image AS fibrillar structures by fluorescence stochastic nanoscopy with an enhanced resolution at least 10-fold higher than that achieved with conventional, diffraction-limited techniques. The implementation of dual-color detection, combined with atomic force microscopy, revealed the propagation of individual fibrils in vitro. In cells, labeled protein appeared as amyloid aggregates of spheroidal morphology and subdiffraction sizes compatible with in vitro supramolecular intermediates perceived independently by atomic force microscopy and cryo-electron tomography. We estimated the number of monomeric protein units present in these minute structures. This approach is ideally suited for the investigation of the molecular mechanisms of amyloid formation both in vitro and in the cellular milieu.

Size and shape variation in late Holocene projectile points of southern Patagonia: A geometric morphometry study Charlin, Judith Emilce; González José, Rolando Since the beginning of systematic archaeological studies in southern Patagonia (Argentina and Chile), projectile points have played an important role as cultural markers. A sequence of projectile point types was established according to their changes in size and shape. These stone tools, along with others cultural evidences, sensed to differentiate a series of "cultural periods," which were, for decades, the frame of reference to understand the cultural evolution in southernmost Patagonia. Although later researches have questioned several of these assumptions, the classical typology of projectile points continued in use until the present day. The goal of this work is to evaluate size and shape variation in two late Holocene projectile point types, known as Fell. Bird, or Magallanes IV and V points or Patagónicas and Ona points, respectively. These two types are compared using geometric morphometries and multivariate statistical analyses. The reliability in the discrimination between types is tested at the light of reduction. The analyses have shown a major incidence of reduction on shape rather than on size, and on blade rather than on stem. However, in average, types IV and V can be distinguished in terms of size, and stem shape despite reduction. Thus, even though successive cycles of use, damage and resharpening have a great influence over size and shape of projectile points, resharpening techniques are specific enough to maintain the differences of size and shape between types, a pattern that is probably related with functional requirements.; Desde los comienzos de los estudios arqueológicos sistemáticos en el sur de la Patagonia (Argentina y Chile), en la década de los 30’s, las puntas de proyectil han jugado un rol importante como marcadores culturales. De acuerdo con sus cambios en tamaño y forma, se estableció una secuencia de tipos morfológicos de puntas de proyectil. Estos instrumentos Uticos, junto con otras evidencias culturales, sirvieron para diferenciar una serie de “períodos culturales”, los cuales fueron, por décadas, el marco de referencia para entender la evolución cultural en el extremo austral de Patagonia meridional. A pesar de que las investigaciones posteriores han criticado varios de los supuestos básicos con los cuales se construyó esta periodizáción, la tipología clásica continúa en uso hasta hoy. El objetivo del presente trabajo es evaluar la variaciones en tamaño y forma en dos tipos de puntas de proyectil del Holoceno Tardío conocidos como Fell, Bird o Magallanes IV y V, o puntas Patagónicas y Onus, respectivamente. Éstos se consideraron como tipos diagnósticos para distinguir los Períodos IV y V en la secuencia regional de ocupación propuesta por Junius Bird. Aquí se comparan ambos tipos mediante análisis de morfometría geométrica y estadística multivariada. Se prueba la confiabilidad en la discriminación entre tipos a la luz de la reducción. La consideración del tamaño y la forma de las puntas de proyectil como variables independientes, gracias a las técnicas de la morfometría geométrica, ha permitido evaluar la incidencia relativa de la reducción sobre ambas variables, y también en relación con las diferentes partes que componen la punta de proyectil. Los análisis han mostrado una mayor incidencia de la reducción sobre la forma que sobre el tamaño, y sobre el borde que sobre el pedúnculo. Sin embargo, a pesar de los cambios morfométricos producto de la reducción, los tipos IV y V pueden distinguirse, en promedio, en base al tamaño y a la forma del pedúnculo. En consecuencia, si bien los sucesivos ciclos de uso, desgaste y reutilización tienen una gran influencia sobre el tamaño y la forma de las puntas de proyectil, las técnicas de reutilización son lo suficientemente específicas para mantener las diferencias de tamaño y forma entre tipos, probablemente en relación con demandas funcionales.

In vitro replication of bovine herpesvirus types 1 and 5 Marin, Maia Solange; Leunda, Maria Rosa; Verna, Andrea Elizabeth; Faverin, Claudia; Perez, Sandra; Odeón, Anselmo Carlos The aim of this work was to study the in vitro replication of bovine herpesvirus types 1 and 5 (BoHV-1 and 5) at the beginning and end of the logarithmic growth phase of Madin-Darby Bovine Kidney (MDBK) cells. The replication kinetics and size of lysis and infection plaques of the field isolates 09/210 (BoHV-1) and 97/613 (BoHV-5) and the reference strains BoHV-1.1 Los Angeles 38 (LA38), BoHV-1.1 Cooper, BoHV-5a N569 and BoHV-5b A663 were evaluated. The highest mean virus titre was recorded for N569, followed by LA38 and 97/613. For most of the viruses, the virus titre values increased from 24. h post-infection (hpi) up to 48. hpi and then, they remained unchanged up to 72. hpi. However, the virus titre for 09/210 was significantly lower and a slight, steady increase was observed from 24 to 72. hpi. Furthermore, the largest lysis and infection plaques were recorded for 97/613 and LA38, respectively. According to this work, it is evident that there is a relationship between the replication of BoHV and the multiplication stage of MDBK cells. The results of this study contribute to the understanding of the replication behaviour in cell cultures of several strains of BoHV, which is critical for the rational design of in vitro experiments and vaccine production.

Occurrence of shallow gas in the easternmost Lago Fagnano (Tierra del Fuego) Lodolo, Emanuele; Baradello, L.; Darbo, A.; Caffau, Mauro; Tassone, Alejandro Alberto; Lippai, Horacio Francisco; Lodolo, A.; De Zorzi, G.; Grossi, M. High-resolution seismic profiles acquired in the eastern sector of Lago Fagnano, the southernmost ice-free lake in the world, have shown the presence of very shallow gas-bearing layers in the upper sedimentary sequences. The gas-related features observed on seismic profiles include a typical, very strong reflection with reversed polarity, multiple reflections and acoustic blanking that hide subsurface sedimentary and structural features. The top of the acoustically high-amplitude layer is located between 0.3-1.7 m below the lake floor. It generally forms a sharp boundary, often marked by a varying offset probably due to different levels of gas penetration, which could be related to the lithology of the overlying sediments. To confirm the presence of gas, some gravity cores were recovered in places where the blanking effect was most relevant and in the supposed gas-free zone. Sediment core analyses have highlighted the occurrence of significant organic-rich components within the uppermost, largely unconsolidated sedimentary layers, in correspondence of the seismically-detected gassy zone, whereas only a few organic layers were found in the gas-free zone. We assume that the main origin of gas is linked to the presence of a shallow, thin peat-rich layer of Middle-Late Holocene age. In fact, the mapped gassy zone occurs in correspondence of the outlet of the Rio Turbio, the principal tributary of Lago Fagnano, which discharges waters coming from a relatively small sag pond located immediately to the east of the eastern shore of the lake. To date, this is the first evidence of shallow gas in Tierra del Fuego lakes.

Bloom forming cyanobacterial complexes co-occurring in a subtropical large reservoir: Validation of dominant eco-strategies O'farrell, Ines; Bordet, Hugo Facundo; Chaparro, Griselda Noemí In this study, we analyse the spatial distribution of cyanobacterial summer blooms in a large subtropical reservoir located in the Uruguay River, from 2007 to 2011; these extraordinary algal growth events are mainly represented by scum-forming and nitrogen-fixing eco-strategists of the Dolichospermum and Microcystis genera. The use of the eco-strategists approach, based on ecophysiological work and field observations, allowed us to explain the differences in the distribution pattern and temporal dynamics of both cyanobacterial complexes. Spatial differences were produced due to much higher and fluctuating cyanobacterial abundances at the right margin of the reservoir and at the littoral areas closer to the dam. Satellite imagery (LANDSAT 5 TM) clearly depicted the stronger algal development in the reservoir arms and in the section closer to the dam. The Microcystis spp. complex achieved higher density than the Dolichospermum spp. complex. We hypothesise that the hydrological cycle explains the inter-annual fluctuations of the intensity and frequency of cyanobacterial blooms, and that spatial differences in cyanobacterial presence between the reservoir arms, its margins and the main channel is mainly a response to morphometrical and hydrological characteristics.

Morfometría fluvial aplicada a una cuenca urbana en Ingeniero White, República Argentina; Fluvial morphometry applied to an urban watershed in Ingeniero White, República Argentina Campo, Alicia María; Aldalur, Nélida Beatriz; Fernández, Sandra Noemí La morfometría fluvial estudia diversas variables que caracterizan la forma de una cuenca de drenaje. En una cuenca urbana, la intervención humana está presente en el mayor porcentaje de la cuenca y las distintas infraestructuras condicionan el camino del agua. El objetivo de este trabajo es aplicar el método morfométrico de cuencas naturales a una cuenca urbana. El área de estudio (6 km2) drena sus aguas al frente costero y comprende la localidad de Ingeniero White, República Argentina. Se realizó la jerarquización de la red de drenaje. Los índices morfométricos calculados fueron: relación de bifurcación, relación de longitud y relación de elongación. Los parámetros calculados fueron orden de cuenca, área y pendiente media. Se identificaron tres subcuencas con escasa pendiente que presentan eventos de inundación, con mayor peligrosidad con precipitaciones extremas. Los valores de relación de longitud obtenidos indicaron mayor concentración de energía en eventos de grandes avenidas para las tres subcuencas analizadas. Los valores de relación de elongación demostraron que una de las subcuencas es de forma circular y presenta mayor velocidad en las avenidas de la escorrentía. Las dos cuencas más elongadas tienen mayor retardo en las avenidas. El mayor caudal del área de estudio fluye por la cuenca que posee el mayor número de orden y la mayor superficie. Las otras dos cuencas de menor superficie están sujetas a crecientes instantáneas y de respuesta inmediata. Los valores de pendiente y de área obtenidos aplicados a modelos hidrológicos e hidraúlico determinaron la sección de los conductos y canales destinados a evacuar las aguas hacia el estuario. El caudal calculado para el área drenada fue de 22,41 m3/s.; The fluvial morphometry studies several variables that characterize the form of a drainage basin. The aim of this paper is to apply the natural watershed morphometric method to an urban watershed. The study area (6 km2) drains its waters into the waterfront and includes the town of Ingeniero White, República Argentina. Hierarchical organization of the drainage network was done. Three subbasins that have low-gradient flood events, most dangerous extreme rainfall, were identified. The length relationship values showed greater concentration of power in event of major avenues. The elongation relationship values showed that one of the sub-basins is circular and has more speed in the avenues of runoff. The two elongated basins have greater delay in the avenues. The increased flow of the study area flows through the basin that has the largest number of order and the largest area. The other two basins are subject to increasing surface snapshot and immediate response. The slope and area values applied to hydrologic and hydraulic models determined the section of the ducts and channels. The calculated flow for the area drained was 22.41 m3/s.

Water-soluble N-heterocyclic carbene platinum(0) complexes: Recyclable catalysts for the hydrosilylation of alkynes in water at room temperature Silbestri, Gustavo Fabián; Flores, Juan Carlos; De Jesús, Ernesto The synthesis and characterization of new water-soluble platinum(0) complexes bearing sulfonated N-heterocyclic carbene (NHC) and divinyltetramethylsiloxane (dvtms) ligands are described. These complexes, of the general formula (NHC)Pt(dvtms), are active and recyclable catalysts for the hydrosilylation of phenylacetylene and other alkynes at room temperature in water. Our findings indicate that the NHC-Pt(0) bonds are reasonably stable under these catalytic conditions, although hydrolysis is observed at temperatures above 80 °C in pure water. © 2012 American Chemical Society.

La alianza proclamó guerra y esclavitud a la civilización: Representaciones de la guerra de la Triple Alianza a través del periódico paraguayo El Centinela (1867-1868) Johansson, Maria Lucrecia El gobierno de Paraguay durante el transcurso de la guerra de la Triple Alianza (1864-1870) creó cuatro periódicos con el objetivo de difundir una visión triunfalista del conflicto en una sociedad que estaba sufriendo fuertes transformaciones. Estos periódicos de guerra, que se imprimían con papel y tinta fabricados en el país, utilizaron una serie de estrategias para llegar a un público más amplio: se publicaron en guaraní, lengua que hablaba la mayor parte de la población, usaron un tono satírico e incorporaron imágenes. En vista de la relevancia que estos periódicos tuvieron para el gobierno paraguayo, nos interesa analizar cuáles fueron las representaciones de la guerra difundidas por El Centinela (1867-1868), el primer periódico creado durante el conflicto y el que se convirtió en modelo a seguir para los periódicos fundados con posterioridad.; The government of Paraguay during the course of the Triple Alliance War (1864-1870) created four newspapers with the aim to spread a triumphalist vision of the conflict in a society that was suffering strong transformations. These newspapers of war, which were printed with paper and ink made in Paraguay, used a series of strategies to get to a wider public: they were published in Guarani, language spoken by most of the population, they used a satirical tone and incorporated images. In view of the relevancy that these newspapers had for the Paraguayan government, we are interested in analyzing which were the representations of the war spread by El Centinela (1867-1868), the first newspaper created during the conflict and the one that turned into a model for the newspapers founded later.

La dimensión argumentativa en la entrevista de campo: el espacio biográfico como topo fundamental: Estudio de caso; The Argumentative Dimension in a Field Interview: The Biographical Field as an Essential Setting: Case Study Aráoz, Isabel El objetivo del presente trabajo es abordar la dimensión argumentativa presente en la entrevista de campo a partir de un estudio de caso. La entrevista recupera las experiencias de estudiantes beneficiados con becas económicas que posibilitan la permanencia en el nivel educativo superior universitario y la obtención del título percibido como un medio legítimo de ascenso social. Lo argumentativo se construye, fundamentalmente, como un topo biográfico que certifica la posición y la identidad del sujeto entrevistado por medio de la narración de la propia vida. Tomaremos dos entrevistas como ejemplos representativos de un universo mayor. Para el análisis de los argumentos, que concretizan el topo biográfico, utilizaremos como categorías centrales las nociones de “contradicción, problematización, roles argumentativos, actantes y actores, tipos de argumentos” propuestas por Plantin (2004) como dispositivos básicos de la dimensión argumentativa, junto al concepto de “ley de paso” de Toulmin (1958). Podemos advertir que las entrevistas construyen el espacio de lo social a través de la narración de la experiencia individual. El relato de los entrevistados presenta como estructura básica tres momentos característicos: “desventaja, esfuerzo y recompensa”.; The aim of the following paper is to deal with the argumentative dimension, which is introduced in the field interview of a case study. The interviews collect the experiences of students who have economic benefits (scholarships) that make possible their continuance in the university superior level, and thus the obtaining of the degree as a legal mean of social mobility. The argumentative dimension is built, mainly, as a biography that certifies the position and the identity of the individual interviewed, who tells about his or her own life. We are going to take two interviews as examples that represent a major group. We will also take into account as central categories the notions of “contradiction, approaching, argumentative roles, actors, and types of story lines” to make an analysis that builds the biography. These concepts were proposed by Plantin (2004) as the basic elements of the argumentative dimension. We are also going to bear in mind the concept of the “passing law” posed by Toulmin (1958). These interviews build the social space through the narration of the individual experience. The accounts of the people interviewed present three typical moments which are introduced as the basic structure: “disadvantage, effort and reward”.

Indigenous microorganisms as potential bioremediators for environments contaminated with heavy metals Colin, Veronica Leticia; Villegas, Liliana Beatriz; Abate, Carlos Mauricio Heavy metal pollution is one the most serious environmental problems facing our planet today, and immediate solutions are needed. Heavy metals such as copper (Cu) and chromium (Cr) play an important role as trace elements in biochemical reactions, but these metals are toxic at higher concentrations. In our region, mining and industrial activities have led to large-scale copper contamination in the environment. All organisms have homeostasis mechanisms for this metal, but when these controls fail or are exceeded several toxicological processes can develop.Problems involving Cr contamination are related to the fact that Argentina is an important world producer of leather. A chromium compound is used as a tanning agent, which has resulted in severe contamination near tanneries, with a mix of Cr(III) and Cr(VI). At present, the conventional technologies used to remove heavy metals from the environment involve physicochemical processes, which are costly and require large amounts of energy and specialized equipment. However, microbe-based removal is now considered to be an effective alternative method to the conventional processes and is receiving greater levels of interest for potential uses in bioremediation.This review discusses the toxic effects of Cu and Cr on the environment and on human health, as well as possible approaches for bioremediation of these metals using native microbes from our region.

Θαύματα hagiográficos y αὐτόματα de la Edad de Oro Cavallero, Pablo Adrian A partir del mito de la Edad de Oro y de la producción, en ella, de bienes automáticos, se analizan algunas referencias literarias medievales, seleccionadas del género hagiográfico, en las que se producen lo que habitualmente llamamos "milagros" y que se interpretan como una "cristianización" de los fenómenos asombrosos de los paganos antiguos. En unos y otros se busca una "espontaneidad" de bienes que hacen añorar una etapa perdida.; Starting from the myth of the Golden Age and the production of its automatic holdings, some medieval literary references are analyzed selected from the hagiographic genre. There, what we habitually call miracles appear and are interpreted as a Christianization of the amazing phenomena of the ancient pagans. In each others the spontaneity of those holdings seems to be missing a lost stage.

¿Herederos de Mayo y la Constitución de 1853? Liberalismo y antiliberalismo en el debate sobre la reforma constitucional de 1949 Martinez Mazzola, Ricardo Hernan El artículo aborda las reconfiguraciones que los discursos peronista y antiperonista experimentaron en el proceso que condujo a la reforma constitucional de 1949. En particular da cuenta del modo en que la posición ante la tradición liberal se convirtió en un parteaguas en el que se expresó, y profundizó, el enfrentamiento político. Reconstruye los argumentos que peronistas, radicales y socialistas sostuvieron en distintas arenas –el Parlamento Nacional, la tribuna pública, la Convención Constituyente- subrayando cómo en ellos se expresaba una profunda disputa acerca de la historia política argentina y del papel que en esa historia, y en particular en la formulación que en la Constitución de 1853, había cumplido la tradición liberal. El artículo concluye mostrando cómo una perspectiva atenta al carácter co-constitutivo de las identidades permite echar luz sobre la significación de la coyuntura de la reforma constitucional en una historia más larga de las tradiciones políticas argentinas.