Barroco y vitalismo en la construcción de un espacio imaginario: la vida breve (1950) de Juan Carlos Onetti Linares, Maximiliano Las múltiples, intensas, conmovedoras vidas breves narradas por Juan Carlos Onetti parecieran, a veces, carecer de énfasis, transcurrir apagadas casi sin acaecer. Es el momento en que el incipit se enfrenta con la clausura para fundirse y, acaso, autorrectificarse: "Puedo alejarme tranquilo; cruzo la plazoleta y usted camina a mi lado, alcanzamos la esquina y remontamos la desierta calle arbolada, sin huir de nadie, sin buscar ningún encuentro, arrastrando un poco los pies, más por felicidad que por cansancio" (párrafo final de LVB, 294- 295, destacado nuestro). Sin embargo y por eso mismo, como lo demuestra esta novela capital en la narrativa hispanoamericana del siglo XX, el espesor de sus temas, la novedad de los recursos técnicos incorporados en su redacción y la demoledora belleza conque resultó plasmada configuran una escritura gozosamente ineludible. Este cierre remite al principio, resemantiza el "mundo loco" de la Queca porque ahora ya no es un hablar sobre el carnaval sino que ahora se está, concretamente, en el carnaval, un tempo que Onetti lleva a la ficción para que ésta se introduzca en lo real: los personajes han elegido un disfraz (Calderón planteaba con el "Gran Teatro del Mundo" que cada uno cumple el rol que Dios distribuyó entre los hombres: uno es rey, el otro es mendigo, el otro panadero, el de más allá un joyero, y el que está al lado un sirviente y lo importante no es salirse del rol sino cumplirlo lo mejor posible) y con él escapan, disparan, se fugan, se evaden, se liberan de la realidad y por eso entran en otra realidad. Los límites entre realidad y realidad son a veces lábiles pero siempre hay una frontera que es necesario cruzar. El barroco y el vitalismo como componentes esenciales de los devenires textuales en onetti.

Oscillations and translation of a free cylinder in a viscous confined flow D'angelo, María Verónica; Hulin, Jean-Pierre; Auradou, Harold An oscillatory instability has been observed experimentally on an horizontal cylinder free to move and rotate between two parallel vertical walls of distance H. The vertical motion of the cylinder, its rotation about its axis, and its transverse motion across the gap have been investigated as a function of its diameter D, its density ρs, of the mean vertical velocity U of the fluid, and of its viscosity ν. The relevant Reynolds number Re is shown to be based on the cell aperture H and on the relative velocity Vr between the fluid and the cylinder. For a blockage ratio D/H above 0.5 and Re above 20, oscillations of the rolling angle of the cylinder about its axis and of its transverse coordinate in the gap were observed together with periodic variations of the vertical velocity. For a given fluid-cylinder pair, the relative velocity Vr as well as the frequency f and the amplitude of the transverse velocity for these oscillations are nearly independent of the flow velocity U. For given cylinder density and fluid characteristics, f is also nearly independent of the ratio D/H in the range investigated. The oscillations could be observed down to values of Re as low as 30: this is lower than usual values for vortex shedding in confined geometries, which suggests that one might deal with a different instability mechanism.

PPARγ ligand treatment inhibits cardiac inflammatory mediators induced by infection with different lethality strains of Trypanosoma cruzi Penas, Federico Nicolás; Mirkin, Gerardo A.; Hovsepian, Eugenia; Cevey, Ágata Carolina; Caccuri, Roberto Luis; Sales, Maria Elena; Goren, Nora Beatriz Trypanosoma cruzi (T. cruzi), the etiological agent of Chagas' disease, causes cardiac alterations in the host. Although the main clinical manifestations arise during the chronic stage, the mechanisms leading to heart damage develop early during infection. In fact, an intense inflammatory response is observed from acute stage of infection. Recently, peroxisome proliferator-activated receptors (PPARs) have attracted research interest due to their participation in the modulation of inflammation. In this work we addressed the role of 15-Deoxy-∆12,14 ProstaglandinJ2 (15dPGJ2), a PPARγ natural ligand in the regulation of inflammatory mediators, in acute and chronic experimental mouse models of Chagas' disease with the RA and K98 T. cruzi strains, respectively. This work demonstrates that 15dPGJ2 treatment inhibits the expression and activity of inducible nitric oxide synthase (NOS2) as well as TNF-α and IL-6 mRNA levels. Also, expression and activity of metalloproteinases 2 (MMP-2) and 9 (MMP9) were inhibited by 15dPGJ2. Moreover GW9662, a specific PPARγ antagonist, revealed the participation of other signaling pathways since, in GW9662 presence, 15dPJG2 had a partial effect on the inhibition of inflammatory parameters in the acute model of infection. Accordingly, NF-κB activation was demonstrated, assessing p65 nuclear translocation in the hearts of infected mice with both T. cruzi strains. Such effect was inhibited after 15dPGJ2 treatment. Our findings support the concept that in vivo PPARγ and NF-κB pathways are implicated in the inhibitory effects of 15dPGJ2 on inflammatory mediators at different times depending on whether the infection is caused by the lethal or non-lethal T. cruzi strain.

The opening of the Magellan Strait and its geodynamic implications Ghiglione, Matias; Navarrete Rodríguez, Ángela Teresa; Gonzalez Guillot, Mauricio Alberto; Bujalesky, Gustavo Gabriel The existence of a Neogene-Quaternary rift system responsible for the opening of the eastern Magellan strait has been one of the more peculiar tectonic features of the southernmost Andes since its discovery more than a decade ago. However, until now there has been no explanation pinpointing the specific tectonic factors that led to the development of the rift. This work focuses on the interaction between the fault systems and the tectonic regimes that have affected Tierra del Fuego north of the South America–Scotia left lateral strike-slip plate boundary. Due to a good match between a Jurassic extensional fault array orientation and the principal stress directions related to the strike-slip plate boundary, we conclude that Jurassic transfer faults reactivated extensionally generating the Magellan rift system. This process was enhanced by northward continental drift, and has implications for the geodynamic behind the separation of South America from Antarctica.

Anxiogenic-like effects of Uncaria tomentosa (Willd) DC aqueous extract in an elevated plus-maze test in mice: a preliminary study Bigliani, María Celeste; Rosso, María Celeste; Zunino, María Paula; Baiardi, Gustavo Carlos; Ponce, Andrés Alberto The purpose of this study was to examine the effect of orally administered Uncaria tomentosa aqueous extracts (UTE) (Willd. ex Roem. & Schult.) DC. (Rubiaceae) during 7, 15, 30 and 90 days of treatment on the expression of anxiety, as expressed in the elevated plus maze test in male Albino Swiss mice. UTE revealed an anxiogenic effect in relation to the control group at 15 and 30 days, but it was reversed after 90 days of administration, without affecting the locomotor activity or any deleterious effects on the overall performance of the animal, either for its ambulation, or clinical status, and body weight and organ weight/body weight from liver, lung and kidney were unaffected. These biphasic effects are usually indicative of heterogeneity in sites of action due to the presence of many alkaloids (speciophylline, uncarine F and uncarine E) and flavanols (catechin and epigallocatechin) identified and isolated from UTE.

Analysis of the pX region of bovine leukemia virus in different clinical stages of Enzootic Bovine Leukemia in Argentine Holstein cattle Panei, Carlos Javier; Serena, Maria Soledad; Metz, German Ernesto; Bravi, Maria Emilia; Gonzalez, Ester Teresa; Echeverria, Maria Gabriela Bovine leukemia virus (BLV) infection in cattle causes Enzootic Bovine Leukemia (EBL). About 30% of infected cattle develop persistent lymphocytosis (PL), a 0.1–5% develops tumors, and a 70% remains asymptomatic in an aleukemic stage (AL). Regulatory genes of BLV (Tax, Rex, R3 and G4) are located in a region known as pXBLV. The variability of those genes had been postulated with the progression of the disease. The aim ofthis work was to compare the wild-type proviral pXBLV region at different stages of BLV natural infected cattle from Argentine Holstein. Pairs of primers were designed to amplify the proviral pX region of 12 cattle by PCR, and products were then sequenced, aligned and compared both with each other and with the reference sequence. Results show a divergence percentage from 0 to 6.1 for the Tax gene, from 0 to 9.4% for the Rex gene, from 0 to 12.1% for the R3 gene and finally from 0 to 6.5% for the G4 gene. Results obtained with hierarchical clustering showed two clusters well differentiated, where the members of each cluster are cattle that had tumor, PL and AL, not allowing differentiate those two cluster by clinical stage.

Effect of organic calcium salts–inulin systems on hydration and thermal properties of wheat flour Salinas, Maria Victoria; Puppo, Maria Cecilia The aim of this work was to study the effect of calcium acid salts–inulin systems on hydration and thermal properties of wheat flour dough. Wheat flour was enriched with calcium lactate (CaLa2) or calcium citrate (Ca3Ci2) (1080–2520 ppm Ca) and inulin (In) (1%–13%, w/w flour basis). Water absorption (Wabs), moisture content (Mcont), water activity (aw) and relaxation time (λ) of dough were analyzed. Pasting properties during heating–cooling process were studied: peak viscosity (PV), breakdown (BD), final viscosity (FV) and setback 1(SB1) were determined. Temperatures (TpI, TpII) and enthalpy (ΔHgel) of gelatinization of dough were analyzed by DSC. Samples with Ca and In presented lower Wabs than control sample with an In2 dependence, with slight difference between both surface responses. More time for dough development (td) was necessary with Ca3Ci2 than with CaLa2, being td independent of calcium content at In level (≥6.5%). Dough with Ca3Ci2 was more stable with less degree of softening than CaLa2-dough, due to the protein stabilizing effect of citrate ion (Hofmeister series) with a maximum at 6.5% In. Mcont and λ decreased with the increase of In, independently of calcium. Hydration properties directly influenced pasting parameters. The increase in In content decreased viscosity (PV, FV) without affecting BD. SB1 behavior suggests the formation of pastes with low and high stability with CaLa2 and Ca3Ci2, respectively. Gelatinization degree decreased (40%) and retarded (ΔT=10 °C) at high levels of both ingredients. CaLa2 had more influence in hydration and thermal properties of wheat flour–inulin blends, enhancing a high degree of inhibition of gelatinization and leading to pastes with low viscosity after cooling. This behavior was influenced by the presence of inulin.

Evolución de la Trypanosomosis bovina por Trypanosoma vivax en Formosa (Argentina). Años 2007 - 2012 y su potencial dispersión en el país.; Evolution of bovine Trypanosomosis by Trypanosoma vivax in Formosa (Argentina). Years 2007-2012 and its potential spread in the country Monzon, Carlos Manuel; Mancebo, Orlando Antonio; Giménez, Juana Noemí; Russo, Ana Maria En base al diagnóstico parasitológico para para tripanosomas de bovinos, se describe la evolución de la onda epizoótica del T. vivax iniciada en Argentina hacia finales del año 2006. Analiza la frecuencia de animales infectados en los diferentes meses del año, a demás de las diferentes características clínicas y epidemiológicas de esta nueva enfermedad en el ganado de Argentina. En base al historial epidemiológico de esta tripanosomosis en países de la región se alerta sobre la propagación de la enfermedad a las principales regiones ganaderas de la Mesopotamia y de la Pampa Húmeda Argentina.; This paper based on parasitological diagnosis made in cattle for tripanosomes, describes the evolution of the T. vivax epizootic wave started in Argentina at the end of 2006 year. Analyzes the frequency of infected animals in different months of the years, in addition to the clinical and epidemiological characteristics of this new disease in cattle in Argentina. Based on the epidemiological history of this tripanosomosis in neighbors countries it warns about the spread of the disease to the most important domestic livestock of Argentina, especially in the Mesopotamia and the Pampa Humeda regions.

Diamond-Based Thin Film Bulk Acoustic Wave Resonator for Biomedical Applications Zalazar, Martin; Guarnieri, Fabio Ariel Nowadays it is in constant growing the development of thin film bulk acoustic resonators. If the piezoelectric material is going to be implanted in the human body, an important requirement is the biocompatibility of the implant. In this regard, Aluminum Nitride (AlN) has emerged as an attractive alternative for use in biomedical MicroElectroMechanical Systems. Ultrananocrystalline Diamond (UNCD) is a promising material to be used in biomedical applications, due to its extraordinary mulifunctionality; it is exceptional for implantable medical devices requiring stringent biological performance. Since both UNCD and AlN films can be processed via photolithography processes used in microfabrication, the integration of UNCD and AlN films provides the bases for developing a new generation of biocompatible Bio-MEMS/NEMS. Research and development was conducted to produce implantable MEMS devices: Pt/piezoelectric AlN/Pt layer heterostructure was grown and patterned on the UNCD membrane with a Ti adhesion layer. By applying voltages between the top and bottom Pt electrodes layers the piezoelectric AlN layer is energized. The feasibility of the fabrication of biocompatible AlN/diamond-based FBAR structure has been demonstrated.

Representación de los extensionistas rurales argentinos sobre los pequeños productores; Representação dos extensionistas rurais argentinos sobre os pequenos agricultores; Argentine rural extensionists' representation of small farmers Landini, Fernando Pablo Actualmente asistimos a un resurgimiento de la extensión rural en América Latina. Procurando contribuir a la comprensión de los fundamentos psicosociales de las prácticas extensión, se estudió la representación social que los extensionistas tienen de los pequeños productores a partir de una encuesta realizada a técnicos que trabajan en distintas instituciones publicas argentinas (n=219). Las preguntas abiertas fueron categorizadas siguiendo los principios de la Teoría Fundamentada. Luego, los resultados de esta etapa fueron cuantificados, asociados con diferentes variables sociodemográficas y utilizados para la construcción de clusters. Existen cuatro grandes áreas de la representación que se relacionan de manera compleja con distintos modelos de extensión rural. La primera área describe a los productores como aprovechados o dejados de lado por actores más poderosos, la segunda como portadores de escasos recursos para salir adelante, la tercera con características internas negativas y la cuarta como poseedores de capacidades y recursos.; Assistimos atualmente a um ressurgimento da extensão rural na América Latina. Buscando contribuir á compreensão dos fundamentos psicossociais das práticas de extensão, estudou-se a representação social que os extensionistas rurais têm dos pequenos produtores através duma enquete feita a técnicos que trabalham em diferentes instituições públicas da Argentina (n = 219). As perguntas abertas foram categorizadas de acordo com os princípios da Grounded Theory. Depois, os resultados obtidos nesta etapa foram quantificados, relacionados com diferentes variaveis sociodemográficas e utilizados para a construção de aglomerados (clusters). Há quatro áreas principais de representação as quais estão relacionados de forma complexa com diferentes modelos de extensão rural. A primeira área descreve a os produtores como explorados ou deixado de lado por actores sociais mais poderosos, a segunda como tendo recursos limitados para progredir na vida, a terceira como pessoas que têm características internas negativas, e quarto como tendo capacidades e recursos persoais.; Nowadays, rural extension is resurging in Latin America. Aiming at contributing to understand the psychosocial foundations of rural extension practices, the rural extensionists' social representation of small farmers was studied. In this vein, 219 extensionists working in different Argentine public institutions were surveyed. The open questions were analyzed following Grounded Theory. Then, the results of this phase were quantified and related to different socio-demographic variables. Also, a cluster analysis was conducted. Four areas of the representation highlight. One describes small farmers as set aside and taken advantaged of by more powerful social actors; the second as not having resources to 'get ahead'; the third as possessing negative internal characteristics and the last one as owners of useful capacities and resources.

Represión y constitución de subjetividades marginales: una mirada sobre el cuerpo y la movilidad en ciudad de Villa María, Argentina; Repression and formation of marginal subjectivities: a look at the body and mobility on Villa María city, Argentina Aimar, Lucas Alberto; Peano, Alejandra del Valle El presente trabajo presenta algunas reflexiones (desde una perspectiva sociológica centrada en el cuerpo y las emociones) sobre la vivencialidad corporal y emocional de jóvenes de sectores populares afectados por diversas formas de represión policial y segregación urbana en la ciudad de Villa María (provincia de Córdoba, Argentina). En una primera parte se describen las principales características de la temática vinculada al binomio seguridad/inseguridad en nuestro país al hacer especial foco en la provincia de Córdoba y la ciudad de Villa María. Posteriormente, se resumen las nociones de cuerpo piel, cuerpo movimiento y cuerpo imagen, a fin de explicar su productividad para comprender (a través de la lectura de datos recogidos en entrevistas con jóvenes de sectores populares víctimas de represión policial) las marcas corporales que se vinculan con la posibilidad de circular en ciertos espacios, las estructuras sociales y las políticas públicas de seguridad/represión. Los datos son presentados en un recorte que permite entender el modo en que determinadas formas de represión y políticas judiciales/policiales afectan las biografías de los jóvenes y su relación con los entornos (cada vez más hostiles) en los que se desenvuelven. Finalmente, se sostiene que las políticas de seguridad intensifican la desconfianza sobre el otro de clase, especialmente el joven-varón y pobre, alrededor de una configuración corporal donde la construcción de una imagen para el otro; la estigmatización y la sensibilidad represiva; y las imposibilidades de movimiento se arraigan en condiciones estructurales encarnadas y prácticas de represión que para los jóvenes son cotidianas.; This paper aims to present some thoughts (from a sociological perspective centered on the body and emotions) of the experiencing of the body and emotions of young popular sectors affected by forms of police repression and urban segregation in the Villa Maria city (province Córdoba, Argentina). The first part describes the main features of the security/insecurity issue in our country, with particular focus on the Cordoba province and the Villa Maria city. Subsequently we summarize notions of «body-skin», «body-image» and «body-movement», explaining their productivity to understand (through the reading of data collected in interviews with grassroots young victims of police repression) the body marks that are linked with the possibility of circulating in certain spaces, social structures and state politics of security/repression. The data are presented in a cut that allows us to understand how certain forms of political repression and judicial practices affect the biographies of young people and their relationship with (increasingly hostile) environments in which they live. Finally, it is argued that security policies intensify the distrust on the «Other of class» (especially the young- male-poor) in connection with one process where the construction of an image to another; stigma and repressive sensitivity, and the impossibilities of movement; are rooted in structural conditions and repressive practices that the young-male-poor live every day.

Trabajo, desarrollo y clasificación de residuos: transformaciones en el último medio siglo Dimarco, Sabina Alejandra Durante las últimas décadas en casi toda América Latina ha surgido un nuevo actor social: las organizaciones de clasifi cadores urbanos de residuos. El presente artículo analiza ese fenómeno reciente tomándolo como un hecho social que condensa dos profundas transformaciones estructurales que han signado al continente latinoamericano a lo largo del último medio siglo: por un lado, las acontecidas en el mundo del trabajo y que refi eren tanto a los cambios del mercado de trabajo como a aquellos ocurridos en la forma en que se piensa lo que es el trabajo “digno” y, por el otro, en la forma en que se piensa la cuestión del desarrollo en estos países a partir del surgimiento de la cuestión ambiental y las teorías del desarrollo sustentable.

Distintas miradas sobre el plan de inclusión previsional. Un análisis de caso Bravo Almonacid, Florencia El plan de inclusión previsional es una política implementada en el año 2005 de corte universal, destinada a las personas adultas mayores del país. Este trabajo tiene como objetivo analizar dicha política de seguridad social, mostrando diversas miradas sobre el Plan de Inclusión Previsional utilizando técnicas cuali y cuantitativas de recolección de información, como encuestas socio demográficas, entrevistas a ejecutores locales del programa, referentes barriales y destinatarios. A partir de este trabajo se buscará aportar a la discusión sobre las políticas públicas dirigidas hacia las personas mayores en la Argentina a partir del estudio del este programa y sus implicancias en las condiciones de vida de personas mayores en situación de pobreza de nuestro país.; The provisional inclusion plan is a universal policy implemented in 2005, aimed at older adults of the country. This paper aims to analyze that policy of social security, showing different views on it, using qualitative and quantitative data collection techniques, such as socio-demographic surveys, interviews with local program implementers, neighborhood managers and social-policy target. The achieve of this paper is to contribute for the discussion of public policies towards older adults in Argentina from the study of provisional inclusion plan and its implications on living conditions of poor older people in our country.

Anti-melanoma vaccinal capacity of CD11c-positive and CD11c-negative cell populations present in GM-CSF cultures derived from murine bone marrow precursors Campisano, Sabrina Edith; Mac Keon, Soledad; Gazzaniga, Silvina Noemí; Ruiz, María Sol; Dodes Traian, Martín Miguel; Mordoh, Jose; Wainstok, Rosa We have initially shown that DC/ApoNec vaccine can induce protection against the poorly immunogenic B16F1 melanoma in mice. The population of DC obtained for vaccination after 7days culture with murine GM-CSF is heterogeneous and presents about 60% of CD11c+ DC. Therefore, our purpose was to identify the phenotype of the cells obtained after differentiation and its immunogenicity once injected. DC were separated with anti-CD11c microbeads and the two populations identified in terms of CD11c positivity (DC+ and DC-) were also studied. Approximately 26.6% of the cells in DC+ fraction co-expressed CD11c+ and F4/80 markers and 75.4% were double positive for CD11c and CD11b markers. DC+ fraction also expressed Ly6G. DC- fraction was richer in CD11c-/F4/80+ macrophages (44.7%), some of which co-expressed Ly6G (41.8%), and F4/80-/Ly6-G+ neutrophils (34.6%). Both DC+ and DC- fractions displayed similar capacity to phagocyte and endocyte antigens and even expressed levels of MHC Class II and CD80, CD83 and CD86 costimulatory molecules similar to those in the DC fraction. However, only DC/ApoNec vaccine was capable to induce protection in mice (p<0.01). After 24h co-culture, no detectable level of IL-12 was recorded in DC/ApoNec vaccine, either in supernatant or intracellularly. Therefore, the protection obtained with DC/ApoNec vaccine seemed to be independent of the vaccine´s ability to secrete this inflammatory cytokine at the time of injection. In conclusion, we demonstrated that all cell types derived from the culture of mouse bone marrow with GM-CSF are necessary to induce antitumor protection in vivo.

Variabilidad de estrategias tecnológicas líticas durante el Período Formativo (ca. 2400 - 1400 ap) en la puna de Salta Mercuri, Cecilia El presente trabajo de tesis doctoral constituye un aporte al conocimiento de las tecnologías líticas de las primeras sociedades productoras de alimentos de las tierras altas del Noroeste Argentino. El interés es explorar la diversidad de conjuntos líticos que comparten ciertas características contextuales en un área y un tiempo relativamente acotados: la Puna de Salta durante el Formativo. Asimismo, a partir de este estudio tecnológico lítico, el desarrollo del trabajo está orientado a vincular la diversidad de las estrategias de subsistencia, las interacciones sociales y los procesos de transmisión cultural que tuvieron lugar en dos áreas de la Puna salteña.

Skeletogenesis in anurans: cranial and postcranial development inmetamorphic and postmetamorphic stages of Leptodactylus bufonius (Anura: Leptodactylidae) Vera, Miriam Corina; Ponssa, María Laura Osteological studies of anurans generally have focused on the descriptions of adults and larval chondrocrania, including developmental series of chondrocrania. Thus, the changes occurring during postmetamorphic stages have largely been overlooked. Herein, we describe cranial and postcranial skeletogenesis, and change in skull shape through the metamorphic and postmetamorphic development of Leptodactylus bufonius. Several elements, particularly those of the cranium, are already ossified at metamorphic climax; among these elements are the frontoparietals, prootics, premaxillae, maxillae, squamosals, pterygoids, neopalatines, angulosplenials, dentaries, mentomeckelians, and the mesosternum. Determining the exact timing of ossification of some elements is difficult because variation in their development may result from extrinsic factors. The otic region and that of the jaw closure undergo the greatest changes in shape, which may imply functional constraints. The development of many skeletal elements is still incomplete at metamorphosis; thus, the changes occurring postmetamorphically are crucial to achieving the configuration and function of an adult skeleton.

Modeling the influence of MgSO4 invariant points on multiphase reactive transport process during saline soil evaporation Gamazo, P.; Saaltink, M. W.; Carrera, J.; Slooten, L. J.; Bea, Sergio Andrés; Gran, M. In the present work, we modeled a laboratory experiment where a sand column saturated with a MgSO4 solution is subject to evaporation. We used a compositional formulation capable of representing the effect of geochemistry on flow and transport for concentrated solutions under extreme dry conditions. The model accounts for the water sink/sources terms due to hydrated mineral dissolution/precipitation and the occurrence of invariant points, which prescribe the water activity. Results show that the occurrence of the invariant points at the top of the domain could affect the vapor flux at the column top and salt precipitation along the column. In fact, the invariant points occurrence could explain the spatial fluctuation on the salt precipitates formation. Results also suggest that the complex hydrochemical interactions occurring during soil salinization, including osmotic effects, are crucial not only to understand the salt precipitation, but also the evaporation rate.

New records and notes on gasteroid fungi of arid regions in Argentina Kuhar, José Francisco; Castiglia, Valeria Carolina; Zamora, Juan Carlos; Papinutti, Víctor Leandro A survey of gasteroid fungi from arid regions in the La Rioja province (northwestern Argentina) resulted in 20 species of 13 genera. Each species is briefly commented on and descriptions are provided for taxa poorly known or with few records in the world. In addition, photographs of basidiomata and SEM micrographs illustrating basidiospores are provided for most of the taxa. The most noticeable records are Bovista grandipora, new for Argentina, Schizostoma argentinense with few records in the world, and Vascellum intermedium and Disciseda verrucosa, new for South America. In addition, the distribution of the species among the main types of habitat is discussed in relation to spore release and humidity.

Construcciones de género en la escuela secundaria Molina, Guadalupe Esta presentación propone discutir en torno a las construcciones de género que despliegan las y los estudiantes en la escuela secundaria. Observar y analizar de qué modos las y los estudiantes secundarios hacen género (West y Zimmerman, 1999) abre un espacio de indagación que puede ser útil no solo para conocer: 1) cómo se están desarrollando actualmente las relaciones entre chicas y chicos en la escuela, sino también 2)¿cómo la escuela participa de dichas construcciones, desde cierto "régimen de género" (Connell, 2001), y en un tiempo histórico donde variados debates sobre la diversidad sexual, el derecho a decidir sobre la propia sexualidad, el matrimonio, el lugar de la mujer, entre otros, atraviesan la escuela desde vertientes sociales, culturales, políticos y legales más amplias. Para ello tomo como referente empírico parte del material de campo de una investigación etnográfica desarrollada en escuelas secundarias públicas de la Ciudad de Córdoba, que se pregunta por los sentidos y prácticas puestas en juego en las construcciones de género y sexualidad que estudiantes secundarios despliegan en su experiencia escolar. Particularmente, quisiera poner en consideración los procesos de diferenciación producidos entre estudiantes de un 5° año, en el que dos grupos de alumnas ensayan y disputan posicionamientos genéricos al calor de diversos avatares socioculturales y escolares.

Influence of talc genesis and particle surface on the crystallization kinetics of polypropylene/talc composites Castillo, Luciana Andrea; Barbosa, Silvia Elena; Capiati, Numa Jose Talc is a laminar silicate, considered as an excellent nucleating agent for polypropylene (PP) crystallization. However, properties of PP/talc composites depend on the morphology, size, and surface of mineral particles. In this sense, talc from several ores, having different morphology, imparts specific characteristics on these materials. Also, taking into account that PP-talc adhesion is not necessarily good due to the apolar character of PP, talc surface has been modified in order to increase this parameter. In this work, the effects of talc genesis, geomorphologic aspects, and particle surface characteristics on crystallization of PP/talc composites are analyzed. Isothermal crystallization of PP/talc composites was studied by using differential scanning calorimetry, based on Avrami model. The final crystalline morphology of talc-filled PP was analyzed by means optical microscopy. The results show that the blocky talc morphology favors even more the crystallization compared to the platy one, at the same particle size. Taking into account the surface treatment studied in this work, the talc surface is made hydrophobic and the particle delamination is favored. As a consequence, so-modified talc is very effective in increasing the crystallization temperature of PP and the nuclei number that grow during the crystallization with respect to the untreated talc.