Physicochemical study of the formation of complexes between pancreatic proteases and polyanions Lombardi, Julia; Picó, Guillermo Alfredo; Boeris, Valeria The formation of insoluble complexes between proteins and oppositely charged polyelectrolytes was assessed. Two pancreatic enzymes: trypsin and chymotrypsin, and two anionic synthetic polyelectrolytes: polyacrylate and polyvinylsulfonate, were used for the study at the pH range between 3.00 and 5.00. Two different titration curve shapes, representing two insoluble complexes formation mechanisms, were found. The turbidity of enzyme–polyelectrolyte mixtures is related to the increase either in the size or in the quantity of the insoluble complexes. Ionic strength destabilized insoluble complex formation. Finally, the kinetics of the process of insoluble complex formation at different conditions was studied.

La reforma penitenciaria en "el subtrópico de la república" (Tucumán, Argentina, 1881-1927); Prison reform in "the subtropics of the republic" (tucumán, argentina, 1881-1927) González Alvo, Luis Gabriel Este artículo busca contribuir al estudio de la reforma penitenciaria en Argentina entre fines del siglo XIX y principios del siglo XX, tomando como centro de su análisis a la provincia de Tucumán. Sus objetivos consisten en realizar una reconstrucción histórica del proceso de edificación de la penitenciaría, explorar los motivos que impulsaron a la clase dirigente tucumana a emprender una obra de esa envergadura a comienzos de 1880, abordar los discursos que sustentaron la reforma y profundizar sobre los modos en que esta transformación del castigo se llevó a cabo. La reforma penitenciaria, entendida como proyecto de racionalización del castigo, fue mucho más allá de la construcción de edificios especiales, ya que demandaba la creación de una infraestructura administrativa con presupuestos considerables, un gran número de personal calificado, así como una red de instituciones, conocimientos técnicos y un discurso de las ciencias sociales. Estos factores han sido estudiados en lo que respecta a Buenos Aires, pero poco se sabe de casos provinciales. Por esta razón se analizarán los orígenes de la reforma penitenciaria argentina tomando como ejemplo la primera experiencia penitenciaria en Tucumán.; This article seeks to contribute to prison reform studies in Argentina between the late nineteenth and early twentieth century, taking the example of Tucumán province. The aims of this paper are to provide an historical reconstruction of the penitentiary building process, to explore the reasons which prompted the Tucumán political class to undertake a work of this magnitude in early 1880, to analyze the speeches that supported the reform and the ways in which punishment transformation was carried out. Prison reform, understood as a punishment rationalization project, was far beyond the construction of specialized buildings, it demanded the creation of an administrative infrastructure with significant budgets, a large number of qualified staff and a network of institutions, technical knowledge and social sciences discourses. All these factors have been mostly studied for Buenos Aires penitentiary but have hardly been studied in provincial cases. For this reason, the objective of this work is to study the origins of the penitentiary reform analyzing the construction of the first penitentiary in Tucuman.

The Southern Argentina Agile Meteor Radar Orbital System (SAAMER-OS): An Initial Sporadic Meteoroid Orbital Survey in the Southern Sky Janches, D.; Close, S.; Hormaechea, Jose Luis; Swarnalingam, N.; Murphy, Adrian; O'Connor, D.; Vandepeer, B.; Fuller, B.; Fritts, D. C.; Brunini, Claudio Antonio We present an initial survey in the southern sky of the sporadic meteoroid orbital environment obtained with the Southern Argentina Agile MEteor Radar (SAAMER) Orbital System (OS), in which over three-quarters of a million orbits of dust particles were determined from 2012 January through 2015 April. SAAMER-OS is located at the southernmost tip of Argentina and is currently the only operational radar with orbit determination capabilityproviding continuous observations of the southern hemisphere. Distributions of the observed meteoroid speed, radiant, and heliocentric orbital parameters are presented, as well as those corrected by the observational biases associated with the SAAMER-OS operating parameters. The results are compared with those reported by three previous surveys performed with the Harvard Radio Meteor Project, the Advanced Meteor Orbit Radar, and theCanadian Meteor Orbit Radar, and they are in agreement with these previous studies. Weighted distributions for meteoroids above the thresholds for meteor trail electron line density, meteoroid mass, and meteoroid kineticenergyare also considered. Finally, the minimum line density and kinetic energy weighting factors are found to be very suitable for meteroid applications. The outcomes of this work show that, given SAAMER's location, the system is ideal for providing crucial data to continuously study the South Toroidal and South Apex sporadic meteoroid apparent sources.

Cambios climáticos en las sierras de Córdoba (Argentina) durante el holoceno. Aportes a las reconstrucciones climáticas a través del análisis de silicofitolitos del sitio arqueológico El Alto 3 Giorgis, Melisa Adriana; Lopez, María Laura; Rivero, Diego Eduardo; Cingolani, Ana María El análisis de silicofitolitos es una herramienta cada vez más utilizada para la reconstrucciónpaleoclimática. Sin embargo, en Córdoba estas reconstrucciones se han realizado con otras técnicas. Eneste trabajo nos propusimos calcular los índices climáticos internacionales a partir de los silicofitolitos, validar dichos índices utilizando la distribución de la vegetación y clima actual de las sierras, y presentarla primera reconstrucción paleoclimática a través de silicofitolitos para el sitio arqueológico más antiguode Córdoba. Los índices internacionales fueron consistentes con los patrones de distribución de lavegetación y clima actual, aunque el índice de frío fue más confiable y sensible que el índice de aridez.A lo largo de perfil analizado los datos de silicofitolitos indicaron un clima frío y húmedo característicodel un sitio de montaña, pero mostraron importantes variaciones en los índices de frío y aridez. Lareconstrucción climática fue consistente con los trabajos previos, al mostrar un pico de aridez al comienzodel Holoceno, seguido por un clima más húmedo y cálido que el actual, un posterior pico de mayor aridezy calor coincidente con la presencia de la familia Arecaceae y finalmente marca una disminución en latemperatura y aumento de las precipitaciones hasta la actualidad.; The analysis of silicophytoliths is an increasingly used tool for paleoclimatic reconstructions. However, in Córdoba climatic reconstruction has been performed with other techniques. In this work we aimed to calculate international climatic indices through silicophytoliths, validate these indices with the current vegetation and climate distribution in the Mountains, and present the first paleoclimatic reconstruction through silicophytoliths for the oldest archaeological site in Cordoba. The international indices were consistent with the patterns of the current vegetation and climate distribution; though the coolness index was more robust and sensitive than the aridity index. Along the analyzed profile the silicophytoliths indicated a cold and humid/wet climate, which is characteristic of a mountain site, but they showed important variation in the coolness and aridity index. The climatic reconstruction was consistent with the previous studies, since it showed a peak of aridity at the beginning of the Holocene, followed by a wetter and warmer climate than the current climate, a subsequent peak of higher aridity and warm was coincident with the presence of the Arecaceae family, and finally it showed a temperature reduction and precipitation increase until the present.

Proposal to reject the names Cestrum subsessile, Solanum ambrosiacum, S. coronatum, S. diantherum, S. jubeba, S. multiangulatum and S. perianthomega (Solanaceae) from Vellozo´s Flora Fluminensis Knapp, Sandra; Barboza, Gloria Estela; Giacomin, Leandro; Stehmann, Joao

A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: using trophic calculations to identify sources of population-level variation Brasso, Rebecka L.; Chiaradia, André; Polito, Michael J.; Raya Rey, Andrea Nélida; Emslie, Steven D. The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (62.00 ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability.

El Estado y las mujeres, concepciones en clave feminista; State and women, feminist conceptions key Valobra, Adriana María Pensar el Estado sigue presentando cierta urgencia en Argentina pues no ha dejado de tener una gran centralidad como interlocutor de las demandas sociales. Específi camente, procuro recuperar los aportes sustantivos de algunas pensadoras feministas. En particular, y aún a riesgo de que mi recorte pueda encasillarse en el de la colonialidad discursiva, retomaré las contribuciones de la politóloga inglesa Carole Pateman y la jurista estadounidense Catharine MacKinnon. Luego, estableceré algunas consideraciones sobre las derivaciones de sus propuestas y la forma en que otras autoras han aportado con particular eje en la ciudadanía tanto en su faz activa como pasiva. Finalmente, volveré a pensar nuestra práctica y nuestra teoría en el proceso de devenir feminista...; Sparing a thought on the State is still an urgent need in our country because the State has not lost a central place as interlocutor of social demands. Specifi cally, I try to recover the substantial contributions some feminist thinkers have made. In particular, risking that my selection could be typecast into the colonialist discursivity, I will return to the contributions of the English political scientist Carole Pateman and American lawyer Catharine MacKinnon. Then, I will make some comments on the derivations of their proposals and how other authors have contributed to debate, with special emphasis in the citizenship both active and passive. Finally, I will think about our practice and our theory in the process of becoming feminists...

The change in the enviroment of the immscible block stabilizes an unexpected HPC phase in cured block copolymer/epoxy blend Leonardi, Agustina Belen; Zucchi, Ileana Alicia; Williams, Roberto Juan Jose A conventional SAXS study of ordered phases produced in cured block copolymer (BCP)/epoxy blends with different concentrations, led to the unexpected observation of an HPC (hexagonally-packed cylinders) phase for a blend containing a 55:45 volume ratio of both domains. The BCP was polystyrene (PS, Mn = 28 kDa)-b-poly(ethylene oxide) (PEO, Mn = 11 kDa), where PS is the “epoxy-phobic” block and PEO is the “epoxy-philic” block. The epoxy formulation was based on diglycidylether of bisphenol A (DGEBA) and 4,4′-methylenebis(2,6-diethylaniline) (MDEA). A fully cured blend containing 60 wt% BCP, equivalent to 45% volume fraction of PS in the blend, exhibited an unexpected HPC morphology as supported by TEM images and SAXS spectra. The same techniques showed that a lamellar (L) phase was generated at low conversions in the same blend. The L to HPC transition was explained by the diffusion of epoxy–amine species out of the PS-rich phase with the increase in conversion. Order-order transitions in BCP/epoxy blends previously reported were explained by the partial phase separation of the miscible block from the epoxy solvent. These transitions go always in the sense of decreasing the interface curvature (e.g., from HPC to L). The transition reported in this study goes in the opposite sense (from L to HPC) and was generated by the change in environment of the immiscible block during polymerization.

SRAP as an informative molecular marker to study the Fusarium Poae genetic variability Dinolfo, María Inés; Castañares, Eliana; Stenglein, Sebastian Alberto Fusarium poae is one of the Fusarium species isolated from grains associated with Fusarium Head Blight (FHB), whose occurrence has increased in the last years. In this study, a total of 105 F. poae isolates from Argentina, Belgium, Canada, England, Finland, France, Germany, Hungary, Italy, Luxembourg, Poland, Switzerland and Uruguay were evaluated by using sequence-related amplified polymorphism (SRAP) to analyze the capacity of this molecular marker to evaluate the F. poae genetic variability. The molecular analysis showed high intraspecific variability within F. poae isolates and a partial relationship was revealed between variability and the host/geographic origin. Analysis of molecular variance (AMOVA) indicated a high genetic variability in the F. poae collection, with most of the genetic variability resulting from differences within, rather than between American and European populations. The analysis of sequenced SRAP fragments targets into hypothetical proteins from different Fusarium species showing that the SRAP technique not only allows studying F. poae genetic variability, but also targets coding regions into the F. poae genome. To our knowledge this is the first report on genetic variability of F. poae using SRAP technique and also demonstrates the efficacy of this molecular marker to amplify open reading frames in fungus.

Iron cycling during the autocatalytic decomposition of benzoic acid derivatives by Fenton-like and photo-Fenton techniques Nichela, Daniela Alejandra; Donadelli, Jorge Andrés; Caram, Bruno Federico; Haddou, Menana; Rodríguez Nieto, Felipe Jorge; Oliveros,Esther; Garcia Einschlag, Fernando Sebastian In the context of our work on the oxidative degradation of a series of hydroxyl derivatives of benzoic acid (HBAs) by Fenton-like and photo-Fenton processes, we present a comprehensive study of the factors that affect the reduction of Fe(III) species, the rate limiting step in the Fenton reaction. We have investigated: (i) the formation of Fe(III)-HBA complexes, (ii) the ability of these complexes to participate in reductive pathways, and (iii) the formation of intermediate products capable of reducing ferric species.The results show that salicylate-like HBAs form stable bidentate ferric complexes in aqueous solutions at pH 3.0 and that Fe(III) complexation significantly decreases the overall degradation rates in Fenton systems by slowing down Fe(II) production through both dark and photo-initiated pathways. Interestingly, in contrast to ferric complexes of aliphatic carboxylates that undergo a photo-induced decarboxylation upon excitation in the 300-400. nm wavelength range, ferric-salicylate complexes yield Fe(II) and hydroxyl radicals by oxidation of water molecules in the coordination sphere of the metal center. However, their efficiencies are significantly lower than that of the Fe(III) aqua complex. Moreover, Fe(III)-HBA complexes are inert upon excitation of the LMCT bands involving the organic ligand (i.e., 400-600. nm).As observed for other aromatic compounds, Fe(III)-reducing intermediates formed during the Fenton oxidation of HBAs play a key role in iron cycling. The analysis of the primary oxidation/hydroxylation products as well as Fe(III)-reduction studies showed that, among dihydroxy aromatic derivatives, hydroquinone-like structures were much more efficient than catechol-like structures for reducing Fe(III). Although all trihydroxy derivatives produced Fe(II), ring opening reactions prevailed under the conditions of the Fenton reaction.The results of our investigation on the Fenton oxidation of HBA derivatives show that, in each particular case, the complex interplay of the aforementioned factors should be carefully evaluated for developing optimal applications of Fenton processes at a technological level.

La ocupación pleistocénica de Cueva Túnel, Meseta Central de Santa Cruz: un espacio que reúne actividades en torno al procesamiento primario de presas Paunero, Rafael; Frank, Ariel David; Cueto, Manuel Enrique; Skarbun, Fabiana; Valiza Davis, Catalina En el presente trabajo buscamos articular distintos estudios que venimos realizando sobre el Componente Inferior del sitio Cueva Túnel. El mismo se ubica en la localidad arqueológica La María, Meseta Central de Santa Cruz, Argentina. Este componente fue datado en la transición Pleistoceno/holoceno. Se describen las características del paisaje donde se encuentra el sitio, considerando las evidencias de uso, las condiciones para el asentamiento y la obtención de recursos. Durante la descripción del sitio se presenta su estratigrafía, las evidencias cronológicas y las dataciones realizadas, además se sintetiza contextualmente el componente inferior. A su vez, se estudia la diversidad taxonómica de los restos faunísticos registrados y se analizan específicamente los restos de camélidos en relación con la frecuencia de partes esqueletarias, los procesos tafonómicos y las marcas antrópicas que nos informan sobre los procesos de procesamiento realizados por los grupos humanos que ocuparan el sitio. Por último, realizamos el análisis tecnomorfológico y funcional de base microscópica del conjunto lítico. Esto nos permitió discutir procesos de producción y consumo de artefactos y evaluar su articulación desde la perspectiva de la estructuración del espacio. Los resultados indican que el sitio habría funcionado principalmente como un sector de procesamiento primario de presas, dentro del marco de un circuito de movilidad regional.; This paper seeks to discuss the functionality of the Lower Component of site Cueva Túnel through the articulation of different analyses which we have been performing. This site is located in La María archaeological locality, at the Central Plateau of Santa Cruz, Argentina. The lower component is dated to the Pleistocene/Holocene transition. The characteristics of the landscape in which the site is situated are described, taking into consideration the evidence of use and the conditions for settlement and for the acquisition of resources. A contextual synthesis of the lower component is introduced and the stratigraphy, the chronological evidence and the radiocarbon dates are discussed. Besides, the taxonomic diversity of the fauna remains is analyzed. The frequency of skeletal parts, the taphonomic processes and the anthropic marks are analyzed for the chamelids remains. This data sheds light on the processing tasks made by the human groups which occupied the site. Finally, the technomorphological and functional analysis of the lithic assemblage is performed. Based on this information, the processes of production and consumption of tools are discussed. The articulation of these tasks is analyzed from a perspective which takes into account the structuration of the space. Results show that this site must have been used as a place for the primary processing of prey, within the circuit of regional mobility.

Self-centering and damping capabilities of a tension-compression device equipped with superelastic NiTi wires Soul, Hugo Ramon; Yawny, Alejandro Andres The hysteretic damping capacity and high recoverable strains characterizing the superelastic response of shape memory alloys (SMA) make these materials attractive for protection systems of structures subjected to dynamic loads. A successful implementation however is conditioned by functional fatigue exhibited by the SMA when subjected to cyclic loading. The residual deformation upon cycling and the efficiency in material usage are the two most restrictive issues in this sense. In this paper, a device equipped with superelastic NiTi SMA wires and capable of supporting external tension compression loads with optimized properties is presented. It is shown how the introduction of the wires' pre-straining allows for the absorption of deleterious residual deformation without affecting the self-centering capabilities upon unloading, in contrast with what occurs for pre-strained tendons. These features were experimentally verified in an in-scale prototype composed of two 1.2 mm diameter superelastic NiTi SMA wires. In order to numerically assess the dynamic response of a simple structure subjected to seismic excitations, a multilinear superelasticity model for the NiTi wires was developed.

Phylogeny of frogs from the genus Physalaemus (Anura, Leptodactylidae) inferred from mitochondrial and nuclear gene sequences Lourenço, Luciana B.; Targueta, Cíntia P.; Baldo, Juan Diego; Nascimento, Juliana; Garcia, Paulo C. A.; Andrade, Gilda V.; Haddad, Célio F. B.; Recco Pimentel, Shirlei M. Although some species groups have been recognized in the leiuperine genusPhysalaemus, no phylogenetic analysis has previously been performed. Here, weprovide a phylogenetic study based on mitochondrial and nuclear DNA sequences from 41 of the 46 species of Physalaemus. We employed the parsimony criterion using the software TNT and POY and the Bayesian criterion using the software MrBayes. Two major clades were recovered inside the monophyletic Physalaemus: i) the highly supported Physalaemus signifer Clade, which included P. nattereri and the species previously placed in the P. deimaticus and P. signifer Groups; and ii) the Physalaemus cuvieri Clade, which included the remaining species of Physalaemus. Five species groups were recognized in the P. cuvieri Clade: the P. biligonigerus Group, the P. cuvieri Group, the P. henselii Group, the P. gracilis Group and the P. olfersii Group. The P. gracilis Species Group was the same as that previously proposed by Nascimento et al. (2005). The P. henselii Group includes P. fernandezae and P. henselii, and was the sister group of a clade that comprised the remaining species of the P. cuvieri Clade. The P. olfersii Group included P. olfersii, P. soaresi, P. maximus, P. feioi and P. lateristriga. The P. biligonigerus Species Group was composed of P. biligonigerus, P. marmoratus, P. santafecinus and P. riograndensis. The P. cuvieri Group inferred here differed from that recognized by Nascimento et al. (2005) only by the inclusion of P. albifrons and the exclusion of P. cicada. The paraphyly of P. cuvieri with respect to P. ephippifer was inferred in all the analyses. Distinct genetic lineages were recognized among individuals currently identified as P. cuvieri and they were congruent with cytogenetic differences reported previously, supporting the hypothesis of occurrence of formally unnamed species.

The need for herbicide use in direct seeding, promotes more sustainable and implementation of integrated systems. Luna, Virginia; Masciarelli, Oscar Alberto; Travaglia, Claudia Noemi; Marchetti, Gisella; Lucero, Martín; Reinoso, Herminda Elmira Technological advances the Argentine has been in recent years such that now stands at the forefront worldwide. The explosion of agriculture, tillage, GM crops and the widespread use of glyphosate have raised controversy, especially regarding the toxicity of the latter. Before weeds are controlled with tillage and these involve serious problems of erosion and soil degradation. Tillage and herbicides have changed the situation and consequently the sustainability of production systems. Glyphosate plays an important role in this transformation, but were allowed to use, would be replaced by more expensive and dangerous herbicides. Under that is essential to achieve these objectives through high yields very tech practice, it is necessary to introduce new technologies to assist the sector mitigation tools and can coexist using those chemicals that may mitigate high exposure to them through technology capabilities to detoxify crops. This tech package is just something known by the scientific-technical and production industry, but that has innovation in its application. The use of PGPR as biofertilizers is a widespread technique that has been installed as a enhancer of crops and environmentally friendly. Our study is based on countering the abuseof chemicals through a complementary technology to mitigate residual glyphosate in crops.

Spatial patterns of mammal occurrence in forest strips surrounded by agricultural crops of the Chaco region, Argentina Núñez Regueiro, Mauricio Manuel; Branch, Lyn Clarke; Fletcher, Robert J.; Marás, Gustavo Arnaldo; Derlindati, Enrique Javier; Tálamo, Andrés Deforestation is a major cause of biodiversity loss, and the predominant factor driving deforestation is expansion of agriculture. A key step toward successful conservation in agricultural areas is maximizing biodiversity value of remaining forest. In subtropical and tropical regions, forest often is left in narrow strips between agricultural fields under the assumption that biodiversity is sustained. We examined use of forest strips and continuous forest by medium and large-sized mammals in Argentine Chaco with camera trapping and hierarchical Bayesian zero-inflated occupancy models and assessed how use related to ecological traits of species. Almost 70% of the species cited for our study area were not detected or were detected in less than 10% of the sampling units. Ten of the 23 species that occurred in the area were absent from strips or were detected most frequently in continuous forest, including all large-bodied species and forest interior specialists. Low occurrence of mammals in strips and in continuous forest raises major concerns related to long-term persistence of mammals in Chaco. Under current development policies, agriculture will continue to expand in this region, further threatening the second largest forest in South America. Alternative configurations for the forest-agriculture landscape, as well as synergism between landscape configuration and other threats, need to be evaluated and incorporated into policy if the rich mammalian fauna of this region is to be conserved.

Global Invader Impact Network (GIIN): Toward standardized evaluation of the ecological impacts of invasive plants Barney, Jacob N.; Tekiela, Daniel R.; Barrios Garcia Moar, Maria Noelia; Dimarco, Romina Daniela; Hufbauer, Ruth A.; Leipzig Scott, Peter; Nuñez, Martin Andres; Pauchard, Aníbal; Pysek, Petr; Vítková, Michaela; Maxwell, Bruce D. Terrestrial invasive plants are a global problem and are becoming ubiquitous components of most ecosystems. They are implicated in altering disturbance regimes, reducing biodiversity, and changing ecosystem function, sometimes in profound and irreversible ways. However, the ecological impacts of most invasive plants have not been studied experimentally, and most research to date focuses on few types of impacts, which can vary greatly among studies. Thus, our knowledge of existing ecological impacts ascribed to invasive plants is surprisingly limited in both breadth and depth. Our aim was to propose a standard methodology for quantifying baseline ecological impact that, in theory, is scalable to any terrestrial plant invader (e.g., annual grasses to trees) and any invaded system (e.g., grassland to forest). The Global Invader Impact Network (GIIN) is a coordinated distributed experiment composed of an observational and manipulative methodology. The protocol consists of a series of plots located in (1) an invaded area; (2) an adjacent removal treatment within the invaded area; and (3) a spatially separate uninvaded area thought to be similar to pre-invasion conditions of the invaded area. A standardized and inexpensive suite of community, soil, and ecosystem metrics are collected allowing broad comparisons among measurements, populations, and species. The method allows for one-time comparisons and for long-term monitoring enabling one to derive information about change due to invasion over time. Invader removal plots will also allow for quantification of legacy effects and their return rates, which will be monitored for several years. GIIN uses a nested hierarchical scale approach encompassing multiple sites, regions, and continents. Currently, GIIN has network members in six countries, with new members encouraged. To date, study species include representatives of annual and perennial grasses; annual and perennial forbs; shrubs; and trees. The goal of the GIIN framework is to create a standard yet flexible platform for understanding the ecological impacts of invasive plants, allowing both individual and synthetic analyses across a range of taxa and ecosystems. If broadly adopted, this standard approach will offer unique insight into the ecological impacts of invasive plants at local, regional, and global scales.

Magnetic Interactions and Energy Barrier Enhancement in Core/Shell Bimagnetic Nanoparticles Lavorato, Gabriel Carlos; Peddis, Davide; Lima, Enio Junior; Troiani, Horacio Esteban; Agostinelli, Elisabetta; Fiorani, Dino; Zysler, Roberto Daniel; Winkler, Elin Lilian In this work, we studied the dynamic and static magnetic properties of ZnO-core/CoFe2O4-shell and CoO-core/CoFe2O4-shell nanoparticles. Both systems are formed by a core of ∼4 nm of diameter encapsulated in a shell of ∼2 nm of thickness. The mean blocking temperature changes from 106(7) to 276(5) K when the core is diamagnetic or antiferromagnetic, respectively. Magnetic remanence studies revealed the presence of weak dipolar interparticle interactions, where Hint is approximately -0.1 kOe for ZnO/CoFe2O4 and -0.9 kOe for CoO/CoFe2O4, playing a minor role in the magnetic behavior of the materials. Relaxation experiments provided evidence that the magnetization reversal process of CoFe2O4 is strongly dependent on the magnetic order of the core. At 10 K, activation volumes of ∼46(6) and ∼69(5) nm3 were found for CoO/CoFe2O4 and ZnO/CoFe2O4 nanoparticles, respectively, corresponding to one-third and one-fifth of the total shell volume. While the magnetic behavior of ZnO/CoFe2O4 nanoparticles is strongly affected by the surface disorder, the exchange coupling at the CoO/CoFe2O4 interface rules the magnetization reversal and the nanoparticles' thermal stability by inducing a larger energy barrier and promoting smaller switching volume.

Personality and alcohol expectancies discriminate alcohol consumption patterns in female college students Pilatti, Angelina; Cupani, Marcos; Pautassi, Ricardo Marcos To characterize patterns of alcohol use in a sample of Argentinean female college students according to personality traits and alcohol expectancies. Methods: Data from 298 female college students (Mage = 18.27 years; SD = 1.37 years) from the city of Cordoba, Argentina were analysed using multinomial regression. Results: Three drinking categories were identified, abstainers, moderate drinkers and regular drinkers with heavy episodic drinking, and these were differentiated by three personality traits [extraversion, disinhibition (DIS) and experience seeking (ES)] and three alcohol expectancies dimensions (sociability, risk/aggression and negative mood). Regular drinkers with heavy episodic drinking and moderate drinkers had, compared to abstainers, higher scores in extroversion and alcohol expectancies for social facilitation, and lower scores in alcohol expectancies for risk and aggression. Regular drinkers with heavy episodic drinking exhibited, compared to moderate drinkers, higher scores in ES, DIS, extroversion, alcohol expectancies for social facilitation and negative mood alcohol expectancies; as well as lower scores in risk and aggression alcohol expectancies. Conclusion: College women in Argentina with problematic alcohol drinking can be distinguished from those drinking moderately.

Fluorinated networks dynamics studied by means of broadband dielectric spectroscopy Miccio, Luis Alejandro; Otegui, Jon; Penoff, Marcela Elisabeth; Montemartini, Pablo Ezequiel; Schwartz, Gustavo A. The influence of the surface chemical modification on the bulk behavior of epoxy based networks has been studied. In particular, the bulk dynamics of epoxy-amine networks modified with fluorinated side chains has been characterized by means of broadband dielectric spectroscopy (BDS), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The fluorination effect on the structure and dynamics of the materials has been related with the observed changes in both segmental and secondary relaxations. An acceleration of the segmental dynamics as the fluorination degree increases has been clearly observed. As a result, a compromise between fluorine surface enrichment and bulk modification has been proposed for these materials.

NORDIHYDROGUAIARETIC ACID: DUAL BEHAVIOR AS PRO- OR ANTIOXIDANT ON A EUKARYOTIC CELL MODEL (VERO CELLS); Nordihydroguaiaretic acid: Dual behavior as pro- or antioxidant on a eukaryotic cell model (vero cells) Konigheim, Brenda Salome; Aguilar, Juan Javier; Tauro, Laura Beatriz; Rivarola, María Elisa; Contigiani de Minio, Marta Silvia; Núñez Montoya, Susana Carolina Since Nordihydroguaiaretic acid (NDGA), a potent natural antioxidant, can produce oxidation in several cell kinds,mainly by superoxide anion production (O2), the current study was designed to assess its capacity to produce ornot this reactive oxygen species on Vero cell line, with the aim to establish whether this lignan behaves as a pro- orantioxidant. The O2 production was determined by the Nitro Blue Tetrazolium reduction test. Results show that NDGA has a dual-face behavior on this eukaryotic cell model depending on the biological environment and itsconcentration. The NDGA behaved as a pro-oxidant when it was tested single, by means of an increase in O2 production that was directly concentration-dependent. Mixed with an antioxidant (ascorbic acid) or a moderateoxidant (glucose), the NDGA behaved as pro-oxidant at low concentrations and antioxidant at high concentrations.