Biochemical changes in certain enzymes of Lysapsus limellium (Anura: Hylidae) exposed to chlorpyrifos Attademo, Andres Maximiliano; Peltzer, Paola; Lajmanovich, Rafael Carlos; Cabagna Zenklusen, Mariana Cristina; Junges, Celina Maria; Lorenzatti, Eduardo Antonio; Aró, Carolina; Grenón, Paula Different enzyme biomarkers (AChE: acetylcholinesterase, CbE: carboxylesterase, GST: glutathione-Stransferase, CAT: catalase) were measured in digestive tissues of Lysapsus limellum frogs collected from a rice field (RF: chlorpyriphos sprayed by aircraft) and a non-contaminated area (RS: reference site), immediately (24 h) and 168 h after aerial spraying with chlorpyrifos (CPF). CPF degradation was also searched in water samples collected from RF and RS, and found that insecticide concentration was reduced toE6.78% of the original concentration in RF at 168 h. A significant reduction of AChE and CbE activities was detected in L. limellum from RF in stomach and liver at 24 and 168 h, and in intestine only at 24 h, with respect to RS individuals. CAT activity decreased in intestine of L. limellum from RF 24 h and 168 h after exposure to CPF, whereas GST decreased in that tissue only at 24 h. In stomach and liver, a decrease was observed only at 168 h in both CAT and GST. The use of biomarkers (AChE, CbE, GST, and CAT) provides different lines of evidences for ecotoxicological risk assessment of wild frog populations at sites contaminated with pesticides.

Transit timing variation analysis in southern stars: the case of WASP-28 Petrucci, Romina Paola; Jofre, Jorge Emiliano; Melita, Mario Daniel; Gomez, Mercedes Nieves; Mauas, Pablo Jacobo David We present four new transit observations of the exoplanet WASP-28b observed between 2011 August and 2013 October. Employing another 11 transits available in the literature we compute new ephemeris and redetermine the physical parameters of the star and the exoplanet. Considering 3 yr of observations, we find no periodic transit timing variations (TTVs) or long-term variations of the inclination of the orbit, i, or the depth of the transit, k, that could be attributable to the presence of another planetary-mass body in the system. We also study the relations between i and k with different factors that characterize the light curves. The fits suggest a possible weak correlation between k with the red noise factor, β, and the photometric noise rate, PNR, and a weak anticorrelation between i and PNR, although more points are needed to confirm these trends. Finally, the kinematic study suggests that WASP-28 is a thin-disc star.

Helium abundance difference within globular clusters: NGC 2808 Cacciari, C.; Pasquini, L.; Valenti, E.; Käufl, H. U.; Mauas, Pablo Jacobo David Multiple populations have been recently detected in most Galactic globular clusters, even with no significant spread in metallicity. Unusual features of the observed colourmagnitude diagrams can be explained by differences in the He content of the stars belonging to the sub-populations. We report on empirical evidence of He abundance spread in a few globular clusters, with particular attention to NGC 2808, where He abundance variation has been measured in a pair of otherwise identical red giant stars using the HeI 1083 nm line.A quantitative estimate of this difference has been derived by appropriate chromospheric modelling, in very good agreement with stellar evolution requirements.

Statistical study of magnetic cloud erosion by magnetic reconnection Ruffenach, A.; Lavraud, B.; Farrugia, C.J.; Demoulin, P.; Dasso, Sergio Ricardo; Owens, M. J.; Sauvaud, J. A.; Rouillard, A. P.; Lynnyk, A.; Foullon, C.; Savani, N. P.; Luhmann, J. G.; Galvin, A. B. Several recent studies suggest that magnetic reconnection is able to erode ubstantial amounts of the outer magnetic flux of interplanetary magnetic clouds (MCs) as they propagate in the heliosphere. We quantify and provide a broader context to this process, starting from 263 tabulated interplanetary coronal mass ejections, including MCs, observed over a time period covering 17 years and at a distance of 1 AU from the Sun with Wind (1995–2008) and the two STEREO (2009–2012) spacecraft. Based on several quality factors, including careful determination of the MC boundaries and main magnetic flux rope axes, an analysis of the azimuthal flux imbalance expected from erosion by magnetic reconnection was performed on a subset of 50 MCs. The results suggest that MCs may be eroded at the front or at rear and in similar proportions, with a significant average erosion of about 40% of the total azimuthal magnetic flux. We also searched for in situ signatures of magnetic reconnection causing erosion at the front and rear boundaries of these MCs. Nearly ~30% of the selected MC boundaries show reconnection signatures. Given that observations were acquired only at 1 AU and that MCs are large-scale structures, this finding is also consistent with the idea that erosion is a common process. Finally, we studied potential correlations between the amount of eroded azimuthal magnetic flux and various parameters such as local magnetic shear, Alfvén speed, and leading and trailing ambient solar wind speeds. However, no significant correlations were found, suggesting that the locally observed parameters at 1 AU are not likely to be representative of the conditions that prevailed during the erosion which occurred during propagation from the Sun to 1 AU. Future heliospheric missions, and in particular Solar Orbiter or Solar Probe Plus, will be fully geared to answer such questions.

A single algorithm to retrieve turbidity from remotely-sensed data in all coastal and estuarine waters Dogliotti, Ana Inés; Ruddick, K. G.; Nechad, B.; Doxaran, D.; Knaeps, E. Ocean color remote sensing has been shown to be a useful tool to map turbidity (T) and suspended particulate matter (SPM) concentration in turbid coastal waters. Different algorithms to retrieve T and/or SPM from water reflectance already exist, however there are important questions as to whether these algorithms need to be calibrated specifically for different regions. In the present work the potential generality of a semi-empirical single band turbidity retrieval algorithm using the near infrared (NIR) band at 859 nm in highly turbid waters is assessed. For completeness the use of 645 nm in medium to low turbidity waters is also proposed. Radiative transfer simulations and in situ measurements from various European and South American coastal and shallow estuarine environments characterized by high concentrations of suspended sediments are analyzed. Reflectance and turbidity measurements were performed in the southern North Sea (SNS) and French Guyana (FG) coastal waters, and Scheldt (SC), Gironde (GIR) and Río de la Plata (RdP) estuaries. Simulations showed that uncertainty for turbidity estimation associated with different particle types and bidirectional effects is typically less than 6%. When applied to field data from the five different sites, the semi-analytical algorithm performed well: turbidity estimates were within 12% and 22% of in situ values. A good performance was also found when the entire database was analyzed (n = 106) with a mean relative error of 13.7% and bias of 4.8%. The good performance of the algorithm for all these regions, despite differences in sediment characteristics, and the results of the radiative transfer simulations suggest the global applicability of the algorithm to map turbidity up to 1000 FNU. Consequently regional algorithms to retrieve SPM concentration from reflectance can be designed by combining this global algorithm to retrieve T from water reflectance with a regional relationship to convert T to SPM. This has the very practical advantage that the measurements needed to calibrate the latter T/SPM conversion for any new region are much easier and cheaper than in situ reflectance measurements.

A complete radio study of SNR G15.4+0.1 from new GMRT observations Supán, Jorge Leonardo; Castelletti, Gabriela Marta; Joshi, B. C.; Surnis, M. P.; Supanitsky, Alberto Daniel Aims. The supernova remnant (SNR) G15.4+0.1 is considered to be the possible counterpart of the γ-ray source HESS J1818−154. With the goal of getting a complete view of this remnant and understanding the nature of the gamma-ray flux, we conducted a detailed radio study that includes the search for pulsations and a model of the broadband emission for the SNR G15.4+0.1/HESS J1818−154 system. Methods. Low-frequency imaging at 624 MHz and pulsar observations at 624 and 1404 MHz towards G15.4+0.1 were carried out with the Giant Metrewave Radio Telescope (GMRT). We correlated the new radio data with observations of the source at X-ray and infrared wavelengths from XMM-Newton and Herschel observatories, respectively. To characterize the neutral hydrogen (HI) medium towards G15.4+0.1, we used data from the Southern Galactic Plane Survey. We modelled the spectral energy distribution (SED) using both hadronic and leptonic scenarios. Results. From the combination of the new GMRT observations with existing data, we derived a continuum spectral index alpha = -0.62 +- 0.03 for the whole remnant. The local synchrotron spectra of G15.4+0.1, calculated from the combination of the GMRT data with 330 MHz observations from the Very Large Array, tends to be flatter in the central part of the remnant, accompanying the region where the blast wave is impinging molecular gas. No spectral index trace was found indicating the radio counterpart to the pulsar wind nebula proposed from X-ray observations. In addition, the search for radio pulsations yielded negative results. Emission at far-infrared wavelengths is observed in the region where the SNR shock is interacting with dense molecular clumps. We also identified HI features forming a shell that wraps most of the outer border of G15.4+0.1. Characteristic parameters were estimated for the shocked HI gas. We found that either a purely hadronic or leptonic model is compatible with the broadband emission known so far.

Comparison of nitrogen fertilizer demand for wheat production between humid and semi-arid portions of the Argentinean Pampas using a mass balance method Romano, Nicolás F.; Alvarez, Roberto; Bono, Alfredo A.; Steinbach, Haydee S. The Argentinean Pampa is an important grain production region in which nitrogen (N) availability restricts wheat (Triticum aestivum L.) yield. We performed 46 experiments in the Semi-arid Pampa for evaluating soil N supplying capacity using a mass balance approach. The information generated was combined with published results from 58 experiments performed in the Humid Pampa. Average rainfall was 50% lower under semi-arid conditions and soils had half of the clay + silt and total N contents than those of humid environments. Wheat yield under humid scenarios doubled the yield attained under semi-arid ones, and N and rainfall use efficiencies were also higher. A model could be fitted with good performance for estimating N-supplying capacity from mineral and organic soil pools (R2 = 0.53–0.93), absorbed N (R2 = 0.70) and yield (R2 = 0.57). This methodology can be used for estimating fertilizer needs under defined climate- and site-specific scenarios. For the average yields, rainfall and soil conditions of the experimental networks, targeted N supply (soil mineral + fertilizer N) was estimated as 160 kg N ha−1 in the Humid Pampa and 50 kg N ha−1 in the Semiarid Pampa. Current N rates applied by farmers need to be increased under humid conditions and overfertilization occurs under semi-arid ones.

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.