Wnt signalling tunes neurotransmitter release by directly targeting Synaptotagmin-1 Ciani, Lorenza; Marzo, Aude; Boyle, Kieran; Stamatakou, Eleanna; Lopes, Douglas M.; Anane, Derek; McLeod, Faye; Rosso, Silvana Beatriz; Gibb, Alasdair; Salinas, Patricia C. The functional assembly of the synaptic release machinery is well understood; however, how signalling factors modulate this process remains unknown. Recent studies suggest that Wnts play a role in presynaptic function. To examine the mechanisms involved, we investigated the interaction of release machinery proteins with Dishevelled-1 (Dvl1), a scaffold protein that determines the cellular locale of Wnt action. Here we show that Dvl1 directly interacts with Synaptotagmin-1 (Syt-1) and indirectly with the SNARE proteins SNAP25 and Syntaxin (Stx-1). Importantly, the interaction of Dvl1 with Syt-1, which is regulated by Wnts, modulates neurotransmitter release. Moreover, presynaptic terminals from Wnt signalling-deficient mice exhibit reduced release probability and are unable to sustain high-frequency release. Consistently, the readily releasable pool size and formation of SNARE complexes are reduced. Our studies demonstrate that Wnt signalling tunes neurotransmitter release and identify Syt-1 as a target for modulation by secreted signalling proteins.

Amelioration of mercury nephrotoxicity after pharmacological manipulation of organic anion transporter 1 (Oat1) and multidrug associated resistance protein 2 (Mrp2) with furosemide Hazelhoff, Maria Herminia; Trebucobich, Mara S.; Stoyanoff, Tania Romina; Chevalier, Alberto A.; Torres, Adriana Monica Inorganic mercury is a major environmental contaminant. The primary site of mercuryinduced injury is the kidney due to the uptake of Hg(2+) -conjugated organic anions in the proximal tubule, primary across the organic anion transporter 1 (Oat1) at the basolateral membrane. At the luminal side, mercuric ions are eliminated by the multidrug resistanceassociated protein 2 (Mrp2). It was described that furosemide treatment induces up-regulation of Oat1 renal expression. As novel preventive and therapeutic strategies based in pharmacological manipulation of drug transporters are emerging, this study was designed to evaluate the impact of furosemide modulation of Oat1 on the nephrotoxicity induced by HgCl2. Wistar rats were treated with furosemide (6 mg/100 g/ day, s.c.) during 4 days or with HgCl2 (4 mg/kg, i.p.) 18 h before the experiments or with furosemide during 4 days before the HgCl2 injection. Furosemide treatment improved HgCl2-induced tubular injury as assessed by urinary alkaline phosphatase activity, urinary glucose, Oat5 urinary excretion and histopathological studies. Besides, administration of furosemide enhanced mercury urinary excretion, reduced mercury total renal accumulation and increased Mrp2 renal expression. In summary, furosemide improves HgCl2- induced proximal tubule injury up-regulating mercury transporters and thus, increasing renal elimination of the mercuric ions. Hence, pharmacological manipulation of mercury transporters with furosemide might be a preventive strategy to reduce mercury toxicity.

Fotogramas de la Gran Transformación China: still life y 24 City de Jia Zhang-Ke Roldan, Diego Pablo; Pascual, Cecilia María Este artículo explora los vínculos entre cine y ciudad, enfocándose en los procesos de transformación acelerados y de gran envergadura. La intención es demostrar que algunas variantes del cine consiguen agregar piezas fundamentales de la experiencia de transformación urbana. A partir de un análisis de la Gran Transformación China, el artículo reflexiona sobre las intervenciones políticas y estéticas de dos películas de Jia Zhang-Ke: Still Life (2006) y 24 City (2008). La conversión de la economía de planificación en una economía de mercado, la urbanización de china, la desestructuración del comunismo, las migraciones, la ruptura de los vínculos familiares y la relación con el pasado son algunos de los tópicos abordados.; This article explores the links between cinema and city, focusing on the processes of rapid and far-reaching transformation. The aim is to show that some variants of cinema get add key pieces of experience of urban transformation. From an analysis of the Great Transformation China, the article focuses on two films of Jia Zhang-Ke ’s political and aesthetic interventions: Still Life (2006) and 24 City (2008). The conversion of planned economy into a market economy, the urbanization of China, the failure of communism, migration, the breakdown of family ties and the relationship with the past are the discussed topics.

Formulation and quality control of semi-solid containing harmless bacteria by-products: chronic wounds pro-healing activity Sesto Cabral, María Eugenia; Ramos Vernieri, Alberto Nicolás; Macedo, Alexandre Jose ; Trentin, Danielle; Treter, Yaninne; Manzo, Ruben Hilario; Valdez, Juan Carlos Chronic wounds are those that remain in a chronic inflammatory state and fail to follow normal healing process. Infection is one of the most important causes of chronicity. A frequent pathogen isolated from chronic infections is Pseudomonas aeruginosa; refractory to therapy and host immune attack in its biofilm phenotype. Lactobacillus plantarum cultures supernatants (LAPS) interfere with its pathogenic capacity. In addition, LAPS showed bacteriostatic and bactericide properties and is neither cytotoxic nor an inductor of necrosis-apoptosis. LAPSs chemical composition was determined; allowing us to propose a correlation between its constituents and their biological activity. This article shows a pharmaceutical dosage form designed by using LAPS as an API with pro-healing activity and its quality control. Pharmacotechnical and anti-microbial assays were adapted to demonstrate that the vehicle used does not modify LAPS activities. Selected formulation (F100) showed fair mechanical and technological properties. From the in vitro release assays was found an adequate release from the carrier matrix and maintains its anti-pathogenic activity for 6 months. We propose F100 for chronic wounds treatment. The use of harmless bacteria by-products, such as LAPS, to antagonize infectious pathogens that have ability to form biofilm is an efficient and economic approach to treat infected chronic wounds.

Two yeast species Cystobasidium psychroaquaticum f.a. sp. nov. and Cystobasidium rietchieii f.a. sp. nov. isolated from natural environments, and the transfer of Rhodotorula minuta clade members to the genus Cystobasidium Yurkov, A. M.; Kachalkin, A. V.; Daniel, H. M.; Groenewald, M.; Libkind Frati, Diego; de Garcia, Virginia; Zalar, P.; Gouliamova, D. E.; Boekhout, T.; Begerow, D. Many species of dimorphic basidiomycetes are known only in their asexual phase and typically those pigmented in different hues of red have been classified in the large polyphyletic genus Rhodotorula. These yeasts are ubiquitous and include a few species of some clinical relevance. The phylogenetic distribution of Rhodotorula spans three classes: Microbotryomycetes, Cystobasidiomycetes and Exobasidiomycetes. Here, the presented multi-gene analyses resolved phylogenetic relationships between the second largest group of Rhodotorula and the mycoparasite Cystobasidium fimetarium (Cystobasidiales, Cystobasidiomycetes, Pucciniomycotina). Based on the results, we propose the transfer of nine species belonging to the Rhodotorula minuta clade into the genus Cystobasidium. As a result, the clinically relevant species R. minuta will be renamed Cystobasidium minutum. This proposal follows ongoing reassessments of the anamorphic genus Rhodotorula reducing the polyphyly of this genus. The delimitation of the R. minuta clade from Rhodotorula species comprised in Sporidiobolales including the type species Rhodotorula glutinis is an important step to overcome obsolete generic placements of asexual basidiomycetous yeasts. Our proposal will also help to distinguish most common red yeasts from clinical samples such as members of Sporidiobolales and Cystobasidiales. The diagnosis of the genus Cystobasidium is amended by including additional characteristics known for the related group of species. The taxonomic change enables us to classify two novel species with the phylogenetically related members of the R. minuta clade in Cystobasidium. The recently from natural environments isolated species are described here as Cystobasidium psychroaquaticum f.a. sp. nov. (K-833T = KBP 3881T = VKPM Y-3653T = CBS 11769T = MUCL 52875T = DSM 27713T) and Cystobasidium rietchiei f.a. sp. nov. (K-780T = KBP 4220T = VKPM Y-3658T = CBS 12324T = MUCL 53589T = DSM 27155T). The new species were registered in MycoBank under MB 809336 and MB 809337, respectively.

Enseñanza integrada de anatomía e histología en la Facultad de Odontología de la Universidad Nacional de Córdoba, Argentina Castillo, Beatriz C.; Arriaga, Adriana; Bregains, Liliana E.; Gómez, Maria E.; Flores, Viviana Y.; Sanz, Adriana V.; Actis, Adriana Beatriz Introducción: Docentes de anatomía, histología y asesoría pedagógica conformaron un equipo para diseñar e implementar una experiencia de enseñanza integrada (EI) en la Facultad de Odontología, Universidad Nacional de Córdoba, Argentina. El objetivo fue promover una mayor integración entre la anatomía e histología del sistema estomatognático y guiar la transferencia a situaciones clínicas. Materiales y métodos: En 2010 se rediseñó una propuesta sobre EI para su aplicación a la totalidad de alumnos y con todos los docentes, quienes participaron en ateneos interdisciplinarios para la actualización de contenidos, unificación de criterios, etc. Los alumnos realizaron cuatro clases teórico-prácticas y un trabajo práctico elaborado sobre un caso clínico, con la participación de un docente de anatomía y otro de histología. En el trabajo práctico, los alumnos efectuaron una exploración guiada de la cavidad bucal y trabajaron grupalmente para resolver preguntas sobre el caso clínico. Evaluaron cada actividad de EI, indicando aspectos positivos y a mejorar. Los docentes se expresaron a través de una encuesta. Resultados: Los alumnos destacaron que el abordaje integrado les permitió una mejor comprensión y relación de los temas de las dos asignaturas; valoraron el dinamismo, las explicaciones claras y bien ilustradas de las clases, y el trabajo sobre situaciones clínicas. Los docentes consideraron que la EI es una experiencia positiva, desafiante, enriquecedora, que mejora los nexos con sus colegas y alumnos. Conclusiones: La experiencia de EI permitió lograr los objetivos de aprendizaje propuestos para los alumnos y constituyó una valiosa oportunidad formativa para los docentes.

Chemical catalyzed recycling of polymers: catalytic conversion of PE, PP and PS into fuels and chemicals over H-Y Lerici, Laura Carolina; Renzini, Maria Soledad; Pierella, Liliana Beatriz In the following study the termocatalytic degradation of polyethylene of high and low density, (HDPE, LDPE), polypropylene (PP) and polyestyrene (PS) on the H-Y zeolite was performed. The catalytic activity was carried out in a batch reactor at 500 °C. The reaction time was 43,75 min. Liquid product yields ranged from ~42 and ~44% wt% for polyethylenes and PP, while the production of PS showed ~71 wt%. The gaseous products ranged between ~46 and ~52 for PE and PP and ~24 wt% for PS. The PP generated the greatest amount of carbonaceous residues (~10 wt%) whereas the LDPE produced the lowest (~4 wt%).

Influence of the synthesis time in the textural and structural properties of Ni-Containing Mesoporous materials Carraro, Paola María; Eimer, Griselda Alejandra; Oliva, Marcos Iván MCM-41 materials have been synthesized by hydrothermal synthesis, and the influence of the synthesis time variation on the structural and textural properties of the final solids was studied. Nickel-modified samples were synthesized with a molar ratio Si/Ni of 60 and increased days of synthesis from 0 to 7 days. The structures obtained were characterized by X-ray diffraction (XRD) and UV-vis diffuse reflectance (UV–Vis DRS) spectroscopy. XRD patterns of samples are typical of MCM-41 structure, which improves with increasing the time of hydrothermal treatment. XRD and UV–vis studies revealed that the short synthesis times do not allow the proper incorporation of nickel in the structure. It was corroborated that, the synthesis time has an important influence on the properties of mesoporous material modified with Ni.

Preliminary data on growth and enzymatic abilities of soil fungus Humicolopsis cephalosporioides at different incubation temperatures; Datos preliminares sobre el crecimiento y la capacidad enzimática del hongo de suelo Humicolopsis cephalosporioides a diferentes temperaturas de incubación Eliades, Lorena Alejandra; Cabello, Marta N.; Pancotto, Veronica Andrea; Moretto, Alicia Susana; Rago, María Melisa; Saparrat, Mario Carlos Nazareno Background Nothofagus pumilio (Poepp & Endl.) Krasser, known as “lenga” is the most important timber wood species in southernmost Patagonia (Argentina). Humicolopsis cephalosporioides Cabral & Marchand is a soil fungus associated with Nothofagus pumilio forests, which has outstanding cellulolytic activity. However, there is no information about the ability of this fungus to use organic substrates other than cellulose, and its ability to produce different enzyme systems, as well as its response to temperature. Aims The aim of this study was to examine the role of H. cephalosporioides in degradation processes in N. pumilio forests in detail by evaluating the in vitro ability of four isolates of this fungus to grow and produce different lytic enzyme systems, and their response to incubation temperature. Methods The ability of the fungi to grow and produce enzyme systems was estimated by inoculating them on agar media with specific substrates, and the cultures were incubated at three temperatures. Results A differential behavior of each strain in levels of growth and enzyme activity was found according to the medium type and/or incubation temperature. Conclusions A intra-specific variability was found in H. cephalosporioides. Likewise a possible link between the saprotrophic role of this fungus in N. pumilio forests and the degradation of organic matter under stress conditions, such as those from frosty environments, was also discussed.; Antecedentes Nothofagus pumilio (Poepp & Endl) Krasser (N. pumilio), conocido como «lenga», es la especie maderable más importante en el extremo sur de Patagonia (Argentina). Humicolopsis cephalosporioides Cabral & Marchand es un hongo del suelo asociado a bosques de N. pumilio, que tiene una actividad celulolítica excepcional. Sin embargo, no hay información acerca de la capacidad de este hongo para utilizar otros sustratos orgánicos distintos de la celulosa, o para producir diferentes sistemas enzimáticos, así como su respuesta a la temperatura. Objetivos El objetivo de este estudio fue profundizar en el rol que Humicolopsis cephalosporioides tiene en los procesos de degradación en los bosques de N. pumilio a través de la evaluación de la capacidad in vitro de 4 aislamientos de este hongo para crecer y producir diferentes sistemas enzimáticos líticos y su respuesta a la temperatura de incubación. Métodos La capacidad de los hongos para crecer y producir sistemas enzimáticos se estimó a través de su inoculación sobre medios de agar con sustratos específicos, siendo incubados a 3 temperaturas. Resultados Se observó un comportamiento diferencial de cada cepa en el crecimiento y la actividad enzimática de acuerdo con el tipo de medio o la temperatura de incubación. Conclusiones Se observó variabilidad intraespecífica en Humicolopsis cephalosporioides. Asimismo, se discutió la posible relación entre el rol saprotrófico de este hongo en los bosques de N. pumilio y la degradación de la materia orgánica en condiciones estresantes, como las existentes en ambientes fríos.

Ontogeny of the extrafloral nectaries of Vigna adenantha (Leguminosae, Phaseolae) and its relation with floral development Ojeda, Fabiana Soledad; Hoc, Patricia Susana; Galati, Beatriz Gloria; Amela Garcia, Maria Teresa Background: The inflorescences of the genus Vigna Savi have extrafloral nectaries (EFNs) among the flowers whose origin is still unknown. The disposition, anatomy and morphology, as well as the ontogeny of the extrafloral nectaries (EFNs) associated with the inflorescences of Vigna adenantha (G.F.W. Meyer) Maréchal, Mascherpa & Stainier (Leguminosae, Papilionoideae, Phaseolae) were studied. Besides, the ultrastructure of the secretory stage was described. Results: The inflorescence, a raceme, bears a brief globose secondary axis in each node with 2 flowers and 5–7 EFNs, which develop in acropetal direction. Each EFN originates from the abscission of a flower bud that interrupts its development, resulting in an elevated EFN. This secretory structure is formed by a ring of epidermal and parenchymatic cells surrounding a group of elongated central cells. The nectary is irrigated by phloem and xylem. Four developmental stages proceed; each one relates to a different embryological stage of the flowers in each secondary axis. Conclusions: The first functional EFN of each secondary axis of the inflorescence reaches its maturity when both the pollen grains and the embryo sacs are completely developed and the flowers begin to open. The secretion is granulocrine. The following EFNs develop in the same way. Keywords: Extrafloral nectaries Inflorescences Ontogeny Morphology Anatomy Ultrastructure Vigna Leguminosae

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase Cano, María Emilia; Agusti, Rosalia; Cagnoni, Alejandro; Tesoriero, María Florencia; Kovensky, José; Uhrig, Maria Laura; Muchnik, Rosa In this work we describe the synthesis of mono- and divalent β-N- and β-S-galactopyranosides and related lactosides built on sugar scaffolds and their evaluation as substrates and inhibitors of the Trypanosoma cruzi trans-sialidase (TcTS). This enzyme catalyzes the transfer of sialic acid from an oligosaccharidic donor in the host, to parasite βGalp terminal units and it has been demonstrated that it plays an important role in the infection. Herein, the enzyme was also tested as a tool for the chemoenzymatic synthesis of sialic acid containing glycoclusters. The transfer reaction of sialic acid was performed using a recombinant TcTS and 3'-sialyllactose as sialic acid donor, in the presence of the acceptor having βGalp non reducing ends. The products were analyzed by high performance anion exchange chromatography with pulse amperometric detection (HPAEC-PAD). The ability of the different S-linked and N-linked glycosides to inhibit the sialic acid transfer reaction from 3'-sialyllactose to the natural substrate N-acetyllactosamine, was also studied. Most of the substrates behaved as good acceptors and moderate competitive inhibitors. A di-N-lactoside showed to be the strongest competitive inhibitor among the compounds tested (70% inhibition at equimolar concentration). The usefulness of the enzymatic trans-sialylation for the preparation of sialylated ligands was assessed by performing a preparative sialylation of a divalent substrate, which afforded the monosialylated compound as main product, together with the disialylated glycocluster.

Progesterone receptor activation downregulates GATA3 by transcriptional repression and increased protein turnover promoting breast tumor growth Izzo, Franco; Mercogliano, María Florencia; Venturutti, Leandro; Tkach, Mercedes; Inurrigarro, Gloria; Schillaci, Roxana; Cerchietti, Leandro; Elizalde, Patricia Virginia; Proietti Anastasi, Cecilia Jazmín The transcription factor GATA3 is involved in mammary gland development and is crucial for the maintenance of the differentiated status of luminal epithelial cells. The role of GATA3 in breast cancer as a tumor suppressor has been established, although insights into the mechanism of GATA3 expression loss are still required.

Pyrolysis of sunflower seed hulls for obtaining bio-oils Casoni, Andrés Iván; Bidegain, Maximiliano Andrés; Cubbito, María Amelia; Curvetto, Nestor Raul; Volpe, María Alicia Bio-oils from pyrolysis of as received sunflower seed hulls (SSH), hulls previously washed with acid (SSHA) and hulls submitted to a mushroom enzymatic attack (BSSH) were analyzed. The concentration of lignin, hemicellulose and cellulose varied with the pre-treatment. The liquid corresponding to SSH presented a relatively high concentration of acetic acid and a high instability to storage. The bio-oil from SSHA showed a high concentration of furfural and an appreciable amount of levoglucosenone. Lignin was degraded upon enzymatic activity, for this reason BSSH led to the highest yield of bio-oil, with relative high concentration of acetic acid and stability to storage.

De la localización a la movilidad: propuestas teórico-metodológicas para abordar la segregación espacial urbana; From isolation to mobility: theoretical- methodological proposals to understand urban spatial segregation Mera, Gabriela Silvina La noción de segregación espacial es una categoría frecuentemente utilizada en el campo académico para analizar la distribución espacial de la población urbana. A pesar de su extensa aplicación y de los debates teóricos que, en los últimos años, se han desarrollado en torno a ella, han sido escasos los esfuerzos por trasladar estas problematizaciones a propuestas metodológicas críticas e integradoras. El presente artículo se propone constituir un aporte en este sentido. Por un lado, recuperando los principales debates entre los estudios especializados y en la sociología urbana para definir esta noción; y, por otro lado, retomando críticamente algunas herramientas metodológicas utilizadas para medirla. Se propone así una definición compuesta de segregación espacial que contemple tanto la distribución espacial (localización residencial) como las prácticas urbanas cotidianas, interacciones y dinámicas de accesibilidad-exclusión (movilidad), en el marco de las cuales las diferencias y distancias se construyen como tales.
; The notion of spatial segregation is a category often used by scholars to analyze the spatial distribution of urban populations. Despite its extensive application and the recent theoretical debates about it, there have been few efforts to translate these issues into critical and integrated methodological proposals. This article aims to make a contribution in this regard. On one hand, reviewing the major debates to define this notion, among specialized studies and urban sociology; and, on the other, critically revisiting some methodological tools used to measure it. It thus proposes a definition of spatial segregation, composed of spatial distribution (residential location) as well as daily urban practices, interactions and accessibility-exclusion dynamics (mobility), under which differences and distances are constructed.

Insights in the kinetic mechanism of the eukaryotic Baeyer-Villiger monooxygenase BVMOAf1 from Aspergillus fumigatus Af293 Mascotti, María Laura; Kurina Sanz, Marcela Beatriz; Juri Ayub, Maximiliano; Fraaije, Marco Wilhelmus This work reports a detailed kinetic study of the recently discovered BVMOAf1 from Aspergillus fumigatus Af293. By performing steady state and pre-steady state kinetic analyses, it was demonstrated that the rate of catalysis is partially limited by the NADPH-mediated reduction of the flavin cofactor, a unique hallmark of BVMOAf1. In addition, the oxygenating C4a-(hydro)peroxyflavin intermediate could be spectrophotometrically detected and it was found to be the most stable among all analyzed BVMOs. To assess the possible influence of some residues on the kinetic features, model-inspired site-directed mutagenesis was performed. Among the mutants, the Q436A variant showed a slightly broader substrate scope and a better catalytic efficiency. In summary, this study describes for the first time the kinetic parameters for an eukaryotic BVMO.

El efecto de las estructuras de defensa costera en las localidades de Mar Chiquita y Mar de Cobo, provincia de Buenos Aires; The effect of coastal protective structures in Mar Chiquita and Mar de Cobo, Buenos Aires province San Martín, Laura; Bunicontro, Maria Paula; Marcomini, Silvia Cristina; López, Rubén Álvaro La zona localizada entre Mar de Cobo y Mar Chiquita presenta las mayores tasas de erosión del litoral atlántico de laprovincia de Buenos Aires.Esta zona costera evidenció, a lo largo del tiempo, un significativo retroceso de la línea de costa, pero también másrecientemente, las estructuras construidas con la finalidad de mitigar los fenómenos erosivos, han contribuido conimportantes modificaciones al sector costero, sin una planificación regional.Las causas del proceso erosivo tienen origen natural, pero se han potenciado por distintas actividades humanas, que afectarona la deriva litoral, desde la localidad de Mar del Plata a Mar Chiquita.El presente trabajo tiene como finalidad, en primer lugar, realizar un relevamiento y caracterización de las estructuras dedefensa costera, la evaluación del ambiente afectado en cada caso y su clasificación por clase funcional. En segundo lugar sepropone una metodología sencilla para cuantificar el área de influencia de los espigones, que representan la obra de defensamás abundante en la zona, calculada a partir de la longitud del espigón y la extensión de las zonas de acumulación yerosión.Finalmente, se demuestra que existe una relación cuantitativaentre la longitud de los distintos tipos de espigones y sus áreasde influencia, tanto al sur como al norte, según la derivalitoral y su interacción con la dinámica local.; The area located between Mar de Cobo and Mar Chiquita shows the highest rates of erosion from the Atlantic coast of Buenos Aires province. This coastal zone showed over time a significant retreat of the coastline, but also more recently, the structures built to mitigate the erosive phenomenon, have contribute with important changes, without any regional planning. The causes of the erosive process have natural origin, but have been enhanced by different human activities that affected the littoral drift, from Mar del Plata resort to Mar Chiquita. The present work aims, on one hand, to perform the survey and characterization of all the coastal protection structures, the evaluation of the local environment affected and its classification by functional class. Secondly, a simple methodology is proposed to quantify the influence area of the most conspicuous structure in the area, the groins, calculated from the length of the groin and the extent of the erosion and accumulation areas. Finally, a quantitative relation is demonstrated between the length of the different type of groins and its influence area, both south and north, according to the littoral drift and its interaction with the local dynamics.

Requerimientos pregerminativos de maihuenia patagonica y maihueniopsis darwinii, cactáceas endémicas de patagonia; Pre-germinative requirements of maihuenia patagonica and maihueniopsis darwinii, endemic cacti from Patagonia Masini, Ana Carla Ailín; Rovere, Adriana; Pirk, Gabriela Inés Cacti are characteristic plants in arid ecosystems, where they play an important ecological role. Many species are threatened because of habitat destruction and collection for commercial purposes. In South America, Argentina is one of the countries with the greatest cacti richness and endemisms. However, cacti have been scarcely studied, especially the southernmost species. Since the study of cacti’s reproductive biology would help to improve their conservation status, we studied basic physiological aspects of the germination of two endemic species of Argentina and Chile, Maihuenia patagonica (Phil.) Britton & Rose and Maihueniopsis darwinii (Hensl.) F. Ritter var. hickenii (Britton & Rose) R. Kiesling. Germination percentage (G), mean germination time (TMG) and time until germination (IG) of control seeds and seeds subjected to three pre-germinative treatments were evaluated. Treatments were cold moist stratification for 40 days, mechanical scarification with sand and sandpaper, and mechanical scarification with a scalpel. Laboratory assays were performed at 20/10 °C and 12 h light/12 h dark regime during 60 days. In M. patagonica germination in the stratification treatment did not differ from the control, but was higher in the scarification with scalpel. In M. darwinii var. hickenii germination only differed between the stratification and the scarification with scalpel. TMG and IG were higher in the stratification treatment than in the control for M. patagonica, whereas scarification treatments did not differ from the control. As for M. darwinii var. hickenii no differences were detected for TMG, but the IG was lower in the stratification than in the control. Probably both species presents some kind of dormancy, since germination percentages were low (M. patagonica between 8-27 % and M. darwinii var. hickenii between 17-26 %) but seeds presented high viability. Presence of physical dormancy is discarded because control seeds of both species germinated and the presence of non deep physiological dormancy is proposed. The latter was partially overcome by mechanical scarification in M. patagonica. These results are a new contribution to the study of cacti in South America and could help to develop in situ conservation strategies through the restoration of degraded areas.

Assessment of the pollen diet in a wood-dwelling augochlorine bee (Halictidae) using different approaches Dalmazzo, Maria de Los Milagros; Vossler, Favio Gerardo Most studies on bee pollen diet are based on the abundance of each pollen type composing honey or pollen stores of whole nests (pollen counts). In an effort to characterize the diet of the augochlorine bee Augochlora amphitrite, we employed nest and intra-nest pollen analyses and bee flower visitation. In addition, we tested a novel approach, the Index of Relative Importance (IRI), a method that combines pollen counts, pollen volume and frequency of pollen occurrence. Using nest pollen analysis we found that the Ludwigia type dominated pollen counts, comprising 56% of whole nests, and thus would have concluded that this is the only most important pollen source in the diet. Instead we found seven other important sources including Ipomoea alba, I. cairica, Gymnocoronis spilanthoides and Pavonia types as well as 26 new floral hosts using all four methods in combination. Thus, we recommend that other studies of bee diet include these other approaches when possible, and especially the novel approach of IRI.

Foot-and-mouth disease vaccination induces cross-reactive IFN-γ responses in cattle that are dependent on the integrity of the140S particles Bucafusco, Danilo; Di Giacomo, Sebastián Víctor; Pega, Juan Franco; Schammas, Juan Manuel; Cardoso, Nancy Patricia; Capozzo, Alejandra Victoria; Pérez Filgueira, Daniel Mariano Interferon-γ (IFN-γ) recall responses against foot-and-mouth disease virus (FMDV) in FMD vaccinated cattle are utilized to study T-lymphocyte immunity against this virus. Here, a recall IFN-γ assay based on a commercial ELISA was set up using 308 samples from naïve and vaccinated cattle. The assay was used to study cross-reactive responses between different FMDV vaccine strains. Blood samples from cattle immunized with monovalent vaccines containing A24/Cruzeiro/Brazil/55, A/Argentina/2001 or O1/Campos/Brazil/58 strains were tested using purified-inactivated FMDV from homologous and heterologous strains. A24/Cruzeiro was the most efficient IFN-γ inducer in all vaccinated animals, both when included in the vaccine or as stimulating antigen. We demonstrate that this was mainly due to the structural stability of the whole viral particle. These results show that IFN-γ production relies on the presence of 140S particles that can maintain their integrity along the incubation process in vitro, and throughout the vaccine´s shelf-life, when used in vivo.

Los debates de la historia de la danza: ¿un diálogo imposible? Vallejos, Juan Ignacio Este artículo busca, en principio, caracterizar los diferentes modelos de la historiografía de la danza. La historia de la danza ha ido complejizando su capacidad de análisis luego del abandono de los primeros enfoques teleológicos. En la década del noventa tiene lugar un doble desplazamiento que busca, por un lado, actualizar la metodología tradicional de la especialidad y, por el otro, redefinirla sobre la base de su integración a los estudios culturales. Nuestra tesis sostiene que el modelo de la historia cultural, sin pretender ser una opción superadora, provee un camino para el diálogo entre enfoques opuestos en la historia de la danza.