FARGO3D: A new GPU-oriented MHD code Benítez Llambay, Pablo; Masset, Frédéric S. We present the FARGO3D code, recently publicly released. It is a magnetohydrodynamics code developed with special emphasis on the physics of protoplanetary disks and planet-disk interactions, and parallelized with MPI. The hydrodynamics algorithms are based on finite-difference upwind, dimensionally split methods. The magnetohydrodynamics algorithms consist of the constrained transport method to preserve the divergence-free property of the magnetic field to machine accuracy, coupled to a method of characteristics for the evaluation of electromotive forces and Lorentz forces. Orbital advection is implemented, and an N-body solver is included to simulate planets or stars interacting with the gas. We present our implementation in detail and present a number of widely known tests for comparison purposes. One strength of FARGO3D is that it can run on either graphical processing units (GPUs) or central processing units (CPUs), achieving large speed-up with respect to CPU cores. We describe our implementation choices, which allow a user with no prior knowledge of GPU programming to develop new routines for CPUs, and have them translated automatically for GPUs.

Rab GTPases and the Autophagy Pathway: Bacterial Targets for a Suitable Biogenesis and Trafficking of Their Own Vacuoles Lopez de Armentia, María Milagros; Amaya, Celina; Colombo, Maria Isabel Autophagy is an intracellular process that comprises degradation of damaged organelles, protein aggregates and intracellular pathogens, having an important role in controlling the fate of invading microorganisms. Intracellular pathogens are internalized by professional and non-professional phagocytes, localizing in compartments called phagosomes. To degrade the internalized microorganism, the microbial phagosome matures by fusion events with early and late endosomal compartments and lysosomes, a process that is regulated by Rab GTPases. Interestingly, in order to survive and replicate in the phagosome, some pathogens employ different strategies to manipulate vesicular traffic, inhibiting phagolysosomal biogenesis (e.g., Staphylococcus aureus and Mycobacterium tuberculosis) or surviving in acidic compartments and forming replicative vacuoles (e.g., Coxiella burnetti and Legionella pneumophila). The bacteria described in this review often use secretion systems to control the host?s response and thus disseminate. To date, eight types of secretion systems (Type I to Type VIII) are known. Some of these systems are used by bacteria to translocate pathogenic proteins into the host cell and regulate replicative vacuole formation, apoptosis, cytokine responses, and autophagy. Herein, we have focused on how bacteria manipulate small Rab GTPases to control many of these processes. The growing knowledge in this field may facilitate the development of new treatments or contribute to the prevention of these types of bacterial infections.

Early short-term treatment with neutralizing human monoclonal antibodies halts SHIV infection in infant macaques Hessell, Ann J.; Jaworski, Juan Pablo; Epson, Erin; Matsuda, Kenta; Pandey, Shilpi; Kahl, Christoph; Reed, Jason; Sutton, William F.; Hammond, Katherine B.; Cheever, Tracy A.; Barnette, Philip T.; Legasse, Alfred W.; Planer, Shannon; Stanton, Jeffrey J.; Pegu, Amarendra; Chen, Xuejun; Wang, Keyun; Siess, Don; Burke, David; Park, Byung S.; Axthelm, Michael K; Lewis, Anne; Hirsch, Vanessa M.; Graham, Barney S.; Mascola, John R.; Sacha, Jonah B.; Haigwood, Nancy L. Prevention of mother-to-child transmission (MTCT) of HIV remains a major objective where antenatal care is not readily accessible. We tested HIV-1–specific human neutralizing monoclonal antibodies (NmAbs) as a post-exposure therapy in an infant macaque model for intrapartum MTCT. One-month-old rhesus macaques were inoculated orally with the simian-human immunodeficiency virus SHIVSF162P3. On days 1, 4, 7 and 10 after virus exposure, we injected animals subcutaneously with NmAbs and quantified systemic distribution of NmAbs in multiple tissues within 24 h after antibody administration. Replicating virus was found in multiple tissues by day 1 in animals that were not treated. All NmAb-treated macaques were free of virus in blood and tissues at 6 months after exposure. We detected no anti-SHIV T cell responses in blood or tissues at necropsy, and no virus emerged after CD8+ T cell depletion. These results suggest that early passive immunotherapy can eliminate early viral foci and thereby prevent the establishment of viral reservoirs.

Acerca de los inicios de la divulgación del Psicoanálisis en Argentina: un análisis de escuela para padres; About the beginning of the popularization og Psychoanalysis in Argentina: an analysis of school for parents Savio, Ana Karina En este artículo nos proponemos analizar los tres tomos de Escuela para Padres de Eva Giberti. Buscamos, por un lado, reflexionar sobre el dispositivo enunciativo que allí surge (Maingueneau, 1987, 1999; Amossy, 2005) y, por el otro, rastrear el modo o los modos en que se construye, formula y reformula el saber experto en estos textos (Authier, 1993, 1995). El trabajo ha revelado que la divulgadora/enunciadora no se presenta como una simple mediadora entre el público lector y el saber del experto, sino que, por el contrario, las imágenes que se construyen en torno a su figura y al vínculo con el enunciatario presentan distintos matices y generan diversos efectos de sentido en el entramado discursivo. Por otra parte, se ha advertido que el nuevo saber al que se refieren no se manifiesta como inalcanzable o cerrado a la comunidad psicoanalítica.; In this article, we analyze the three volumes titled Escuela para Padres, written by Eva Giberti. We seek, on the one hand, reflect on the enunciative device (Maingueneau, 1987, 1999; Amossy, 2005) and, on the other, consider the mode or the modes in which it is constructed, formulate and reformulate the expert knowledge in these texts (Authier, 1993, 1995). This study has identified that in these texts the enunciator is not presented as a simple mediator between the public readers and the expert knowledge, but, on the contrary, the images that are constructed around its figure and the relation with the addresses have different nuances and generate various sense effects in the discursive framework. On the other hand, it has concluded that the new knowledge they refer to does not appear as out of reach, closed to the psychoanalytic community.

Nanotoxicological Effects of SiO2 Nanoparticles on Spodoptera frugiperda Sf9 Cells Santo Orihuela, Pablo Luis; Foglia, María Lucía; Targovnik, Alexandra Marisa; Miranda, Maria Victoria; Desimone, Martín Federico The application of silica nanoparticles (NPs) in the biomedical field experienced a great development. Thedriving forces for these and future developments are the possibility to design NPs with homogeneous size and structureamenable to specific grafting. Moreover, it is possible to tune the characteristics of the NPs to meet the requirements ofeach specific cell and desired application. Herein, we analyzed the effect of silica NPs of various sizes and surface chargeon the viability of Spodoptera frugiperda cells (Sf9 cell line) with the aim of extending the knowledge of possible toxicityof the NPs in the environment and development of new tools for insect control. Moreover, these results will also contributeto develop more effective systems for gene vectors delivery and recombinant proteins expression. Bare silica NPs of14 nm, 380 nm and 1430 nm as well as amine-modified silica NPs of 131 nm and 448 nm were obtained by the Stöbermethod. The NPs were characterized by DLS and zeta potential measurements. The cell viability was assessed by theMTT test. It was observed that the 14 nm NPs possess the highest toxic effect. Indeed, after 24h, the viability of the cellsexposed to the lower concentration of NPs (0.12 mg/ml) was about 40% of the value obtained for the control cells not exposedto NPs. Moreover, the exposure to other negative charged NPs also causes a lower activity when compared with thecontrol. Alternatively, lower concentrations of positive charged NPs (i.e.: 0.12 or 0.6 mg/ml) demonstrated to stimulatethe proliferation of the cells and higher concentrations (i.e.: 7.2 mg/ml) did not present significant differences with thecontrol. In conclusion, we have demonstrated that the NPs possess an effect that is highly influenced by the size, chargeand concentration. Although, silica NPs are being used in the biomedical field, these results contribute to further understandingthe risk that could be associated to nanoparticles and how these can be modified in order to meet the requirementsof each desired application.

First Steps in the Aggregation Process of Copolymers Based on Thymine Monomers: Characterization by Molecular Dynamics Simulations and Atomic Force Microscopy Garay, Alberto Sergio; Rodrigues, Daniel Enrique; Fuselli, Antonela; Martino, Debora Marcela; Passeggi, Mario Cesar Guillermo Atomistic molecular dynamic simulations were performed to study thestructure of isolated VBT−VBA (vinylbenzylthymine−vinylbenzyltriethylammoniumchloride) copolymer chains in water at different monomeric species ratios (1:1 and 1:4).The geometric parameters of the structure that the copolymers form in equilibrium together with the basic interactions that stabilize them were determined. Atomic force microscopy (AFM) measurements of dried diluted concentrations of the two copolymers onto highly oriented pyrolytic graphite (HOPG) substrates were carried out to study their aggregation arrangement. The experiments show that both copolymers arrange in fiber-like structures. Comparing the diameters predicted by the simulation results and those obtainedby AFM, it can be concluded that individual copolymers arrange in bunches of two chains, stabilized by contra-ions−copolymer interactions for the 1:1 copolymerization ratio at the ionic strength of our samples. In contrast, for the 1:4 system the individual copolymer chains do not aggregate in bunches. These results remark the relevance of the copolymerization ratio and ionic strength of the solvent in the mesoscopic structure of these materials.

Rheological behavior of concentrated skim milk dispersions as affected by physicochemical conditions: change in pH and CaCl2 addition Olivares, María Laura; Achkar, Natalia Patricia; Zorrilla, Susana Understanding the behavior of casein micelles (CM) in concentrated regimes is critical for the design of dairy unit operations such as drying or evaporation but also it is still scarce. In this work, the effect of the decrease in pH and the addition of a calcium salt on concentrated skim milk dispersions was examined by rheometric measurements at 25 °C. Control samples (S1), samples with a pH of 5.8 (S2), and samples with 0.04 M CaCl2 addition (S3) at different concentrations (40, 45, 48, 50, and 52% w/w) were analyzed through flow curves and oscillatory dynamic data by frequency sweep tests. All samples showed a clear shear thinning non-Newtonian behavior and a large dependence on concentration, dispersions being more fluid for samples S2 and S3. A viscosity model for microgels was used to obtain parameters related to the characteristic structure of systems. It was demonstrated that CM had a similar structure for the different physicochemical systems studied and that the decrease of pH and the addition of salt reduced the dispersion stability due to electrostatic and steric potential energy is depleted. Dynamic data showed that dispersions at the highest concentration had dominant and similar elastic behavior and weak gel character. A transition regime from fluid to gel was observed in samples S2 at 45% w/w. No samples obeyed the Cox-Merz rule. This study allowed gaining more understanding related to the structure of CM systems studied.

Intrinsic Disorder to Order Transitions in the Scaffold Phosphoprotein P from the Respiratory Syncytial Virus RNA Polymerase Complex Noval, María Gabriela; Esperante, Sebastian; Molina, Ivana Gisele; Chemes, Lucia Beatriz; de Prat Gay, Gonzalo Intrinsic disorder is at the center of biochemical regulation and is particularly overrepresented among the often multifunctional viral proteins. Replication and transcription of the respiratory syncytial virus (RSV) relies on a RNA polymerase complex with a phosphoprotein cofactor P as the structural scaffold, which consists of a four-helix bundle tetramerization domain flanked by two domains predicted to be intrinsically disordered. Because intrinsic disorder cannot be reduced to a defined atomic structure, we tackled the experimental dissection of the disorder-order transitions of P by a domain fragmentation approach. P remains as a tetramer above 70 °C but shows a pronounced reversible secondary structure transition between 10 and 60 °C. While the N-terminal module behaves as a random coil-like IDP in a manner independent of tetramerization, the isolated C-terminal module displays a cooperative and reversible metastable transition. When linked to the tetramerization domain, the C-terminal module becomes markedly more structured and stable, with strong ANS binding. Therefore, the tertiary structure in the C-terminal module is not compact, conferring "late" molten globule-like IDP properties, stabilized by interactions favored by tetramerization. The presence of a folded structure highly sensitive to temperature, reversibly and almost instantly formed and broken, suggests a temperature sensing activity. The marginal stability allows for exposure of protein binding sites, offering a thermodynamic and kinetic fine-tuning in order-disorder transitions, essential for the assembly and function of the RSV RNA polymerase complex.

Glial Cell-Elicited Activation of Brain Microvasculature in Response to Brucella abortus Infection Requires ASC Inflammasome-Dependent IL-1β Production Miraglia, Maria Cruz; Franco, Miriam M. Costa; Rodríguez, Ana María; Bellozi, Paula M. Q.; Ferrari, Carina Cintia; Farias, Maria Isabel; Dennis, Vida A.; Barrionuevo, Paula; Oliveira, Antonio C. P. de; Pitossi, Fernando Juan; Kim, Kwang Sik; Delpino, María Victoria; Oliveira, Sergio C.; Giambartolomei, Guillermo Hernan Blood-brain barrier activation and/or dysfunction are a common feature of human neurobrucellosis, but the underlying pathogenic mechanisms are largely unknown. In this article, we describe an immune mechanism for inflammatory activation of human brain microvascular endothelial cells (HBMEC) in response to infection with Brucella abortus Infection of HBMEC with B. abortus induced the secretion of IL-6, IL-8, and MCP-1, and the upregulation of CD54 (ICAM-1), consistent with a state of activation. Culture supernatants (CS) from glial cells (astrocytes and microglia) infected with B. abortus also induced activation of HBMEC, but to a greater extent. Although B. abortus-infected glial cells secreted IL-1β and TNF-α, activation of HBMEC was dependent on IL-1β because CS from B. abortus-infected astrocytes and microglia deficient in caspase-1 and apoptosis-associated speck-like protein containing a CARD failed to induce HBMEC activation. Consistently, treatment of CS with neutralizing anti-IL-1β inhibited HBMEC activation. Both absent in melanoma 2 and Nod-like receptor containing a pyrin domain 3 are partially required for caspase-1 activation and IL-1β secretion, suggesting that multiple apoptosis-associated speck-like protein containing CARD-dependent inflammasomes contribute to IL-1β-induced activation of the brain microvasculature. Inflammasome-mediated IL-1β secretion in glial cells depends on TLR2 and MyD88 adapter-like/TIRAP. Finally, neutrophil and monocyte migration across HBMEC monolayers was increased by CS from Brucella-infected glial cells in an IL-1β-dependent fashion, and the infiltration of neutrophils into the brain parenchyma upon intracranial injection of B. abortus was diminished in the absence of Nod-like receptor containing a pyrin domain 3 and absent in melanoma 2. Our results indicate that innate immunity of the CNS set in motion by B. abortus contributes to the activation of the blood-brain barrier in neurobrucellosis and IL-1β mediates this phenomenon.

Use of phytoplankton assemblages to assess the quality of coastal waters of a transitional ecosystem: Río de la Plata estuary Sathicq, María Belén; Gomez, Nora; Bauer, Delia Elena; Donadelli, Jorge Luis Among the estuarine ecosystems under anthropogenic stress, the Río de la Plata can represent a case study to help identify phytoplanktonic species diagnosing and warning about water quality changes. The freshwater tidal zone on the coast of Argentina is used for several purposes, including recreational and navigational activities and the provision of drinking water. We analyzed the relationship between the abundance of the phytoplanktonic species, changes in water quality (linked to enrichment with nutrients and organic matter) and the land use on the coast of Argentina. A canonical correlation analysis (CCA) allowed us to identify two environmental gradients, one related to anthropogenic activities, where the most influential factors were BOD5, DIN, PO4 3- and DO, and a second gradient related to turbidity and conductivity. The relative abundances of 24 species were significantly correlated with the deterioration of the water quality. This set of tolerant species is mostly composed of taxa considered C-strategists, and the most represented group was the Chlorococcalean algae. The percentage of this group can provide an early warning indicator of the impairment of the water quality; its abundance exceeded 30% at those sites with a bad water quality (reaching 19000 cell mL-1), and were less than 15% (300 cell mL-1) in sites with a good water quality.The use of a reduced group of species constitutes a potential tool for monitoring, complementing another common indicators such as chlorophyll . a or the total density of phytoplankton. Considering that most of these tolerant species are widely distributed it is possible to employ them as a biomonitor in other freshwater zones of temperate estuaries.

Flower reshaping in the transition to hummingbird pollination in Loasaceae subfam. Loasoideae despite absence of corolla tubes or spurs Strelin, Marina Micaela; Benitez-Vieyra, Santiago Miguel; Ackermann, Markus; Cocucci, Andrea Aristides Many angiosperm lineages present transitions from bee to hummingbird pollination. The flower design in most of these lineages includes either corolla tubes or nectar spurs, structures that commonly experienced an elongation with the acquisition of hummingbird pollination. It is proposed that this increases the fit between the bird head and flower structures, and isolates or partially blocks bees from the interaction. But can this transition occur if the ancestral flower design lacks tubes or spurs? Here we focus on the transition from bee to hummingbird pollination in the Loasaceae subfamily Loasoideae. Loasoideae flowers have radial corollas with separated petals; therefore, they do not display corolla tubes nor nectar spurs. These flowers also present a whorl of nectar scales and staminodes, unique to the subfamily, which is involved in flower–pollinator fit and in nectar harvesting. To explore flower shape adaptation to hummingbird pollination, we tested for correspondence between pollinators and flower shape in Loasoideae. In order to achieve this, we first compared the evolutionary history of flower phenotype and pollination mode, and then used stochastic character mapping and geometric-morphometric variables in a comparison of alternative evolutionary models. The results of our study suggest that the transition from bee to bird pollination was accompanied by changes in the shape of the staminodial complex, along with the evolution of relatively closed corollas. Moreover, while bird pollination seems to be the end point in the evolution of pollination syndromes in many angiosperm lineages, rodent pollinated flowers probably evolved from ancestral bird pollinated flowers in Loasoideae. Our findings suggest that the evolution of bird pollinated flowers from ancestral bee pollinated flowers does not require the presence of corolla tubes or spurs, and can take place as long as the flower design includes structures participating in flower–pollinator fit.

Biología reproductiva y citogenética de Distichiaa muscoides (Juncaceae) Gonzáles, Paul; Suni, Mery; Deanna, Rocío; Scaldaferro, Marisel Analía; Castañeda, Elena; Ramírez, Wilfredo; Valencia, Niels; Cano, Asunción El género Distichia Nees & Meyen (Juncaceae) está formado por tres especies nativas de Sudamérica, siendo Distichia muscoides Nees & Meyen la más ampliamente distribuida (Kirschner et al., 2002). Esta especie dioica es el componente principal de los bofedales, ecosistema muy importante de la región altoandina. En este trabajo se estudiaron distintos aspectos biológicos de D. muscoides como: 1) la viabilidad del polen por medio de métodos indirectos de coloración; 2) la receptividad estigmática a través de una prueba con peróxido de hidrógeno; 3) la viabilidad de las semillas mediante su germinación; y 4) sus datos citogenéticos, empleando la técnica de bandeo cromosómico fluorescente CMA/DA/DAPI. Los resultados muestran que las flores estaminadas presentan polen con un porcentaje alto de viabilidad (100%); las flores pistiladas alcanzan la receptividad estigmática una vez que las ramas del estigma desarrollan su máxima longitud (4 mm) y permanecen en este estado al menos durante dos días. El númeropromedio de óvulos por ovario es 34, y el número promedio de semillas por fruto es 25. Las semillas germinaron a partir del día 15, mostrando 92% de germinación y un tiempo promedio de germinación de 18,4 días. La especie posee 2n = 80-84 cromosomas y el bandeo de fluorescencia mostró dos pares de bandas terminales CMA+/DAPI-, asociadas a regiones organizadoras nucleolares (NORs). Se reportan por primera vez datos reproductivos y cariológicos para esta especie.

Distribution of Pyrethroid Resistant Populations of Triatoma infestans in the Southern Cone of South America Bustamante Gomez, Marinely; Gonçalves Diotaiuti, Liléia; Gorla, David Eladio A number of studies published during the last 15 years showed the occurrence of insecticide resistance in Triatoma infestans populations. The different toxicological profiles and mechanisms of resistance to insecticides is due to a genetic base and environmental factors, being the insecticide selective pressure the best studied among the last factors. The studies on insecticide resistance on T. infestans did not consider the effect of environmental factors that may influence the distribution of resistance to pyrethroid insecticides. To fill this knowledge gap, the present study aims at studying the association between the spatial distribution of pyrethroid resistant populations of T. infestans and environmental variables. A total of 24 articles reporting on studies that evaluated the susceptibility to pyrethroids of 222 field-collected T. infestans populations were compiled. The relationship between resistance occurrence (according to different criteria) with environmental variables was studied using a generalized linear model. The lethal dose that kills 50% of the evaluated population (LD 50 ) showed a strong linear relationship with the corresponding resistance ratio (RR 50 ). The statistical descriptive analysis of showed that the frequency distribution of the Log(LD 50 ) is bimodal, suggesting the existence of two statistical groups. A significant model including 5 environmental variables shows the geographic distribution of high and low LD 50 groups with a particular concentration of the highest LD 50 populations over the region identified as the putative center of dispersion of T. infestans.The occurrence of these two groups concentrated over a particular region that coincides with the area where populations of the intermediate cytogenetic group were found might reflect the spatial heterogeneity of the genetic variability of T. infestans, that seems to be the cause of the insecticide resistance in the area, even on sylvatic populations of T. infestans, never before exposed to pyrethroid insecticides, representing natural and wild toxicological phenotypes. The strong linear relationship found between LD 50 and RR 50 suggest RR 50 might not be the best indicator of insecticide resistance in triatomines.

Physiological response and sulphur accumulation in the biomonitor Ramalina celastri in relation to the concentrations of SO2 and NO2 in urban environments Mateos, Ana Carolina; Gonzalez, Claudia M. This study extends the current knowledge regarding the use of different tools for monitoring atmospheric pollution. The chemical response of the lichen Ramalina celastri was evaluated through physiological parameters and sulphur accumulation in relation to the SO2 and NO2 concentrations present in the air at the monitoring sites with different emission sources, in order to assess the atmospheric pollution in urban environments. In this way, it was possible to establish different levels of air quality using simultaneous measurements of gaseous pollutants in the air and of parameters for the exposed biomonitor, as well as to determine the relationship among them and their association with the different emission sources present. Thalli of Ramalina celastri were transplanted at sites with different pollutant emission sources within the city of Córdoba, and simultaneously the concentrations of SO2 and NO2 were measured at the same sampling sites. Pigment content, hydroperoxy conjugated dienes, malondialdehyde and sulphur accumulation were quantified in the lichen and the pollution index was calculated. The results showed that high concentrations of atmospheric SO2 in urban environments can be detected with certainty by measuring sulphur accumulation on the biomonitor. Although this relationship has often been assumed, it has not been confirmed by using simultaneous measurements. This biomonitor allowed different air quality levels to be identified in relation to the concentrations of NO2 and SO2 in Córdoba city. The biomarkers that best reflected the damage caused by pollutants on the lichen were pollution index, hydroperoxy conjugated dienes and malondialdehyde, which revealed a strong association with the most polluted areas in the city (industrial and heavy traffic sites).

Structural Insights into the HWE Histidine Kinase Family: The Brucella Blue Light-Activated Histidine Kinase Domain Rinaldi, Jimena Julieta; Arrar, Mehrnoosh; Sycz, Gabriela; Cerutti, Maria Laura; Berguer, Paula Mercedes; Paris, Gastón; Estrin, Dario Ariel; Marti, Marcelo Adrian; Klinke, Sebastian; Goldbaum, Fernando Alberto In response to light, as part of a two-component system, the Brucella blue light-activated histidine kinase (LOV-HK) increases its autophosphorylation, modulating the virulence of this microorganism. The Brucella histidine kinase (HK) domain belongs to the HWE family, for which there is no structural information. The HWE family is exclusively present in proteobacteria and usually coupled to a wide diversity of light sensor domains. This work reports the crystal structure of the Brucella HK domain, which presents two different dimeric assemblies in the asymmetric unit: one similar to the already described canonical parallel homodimers (C) and the other, an antiparallel non-canonical (NC) dimer, each with distinct relative subdomain orientations and dimerization interfaces. Contrary to these crystallographic structures and unlike other HKs, in solution, the Brucella HK domain is monomeric and still active, showing an astonishing instability of the dimeric interface. Despite this instability, using cross-linking experiments, we show that the C dimer is the functionally relevant species. Mutational analysis demonstrates that the autophosphorylation activity occurs in cis. The different relative subdomain orientations observed for the NC and C states highlight the large conformational flexibility of the HK domain. Through the analysis of these alternative conformations by means of molecular dynamics simulations, we also propose a catalytic mechanism for Brucella LOV-HK.

Primera detección de ondas gravitacionales; First detection of gravitational waves Moreschi, Osvaldo Mario Presentamos una breve descripción de la primera detección de ondas gravitacionales. Aprovechamos para comentar aspectos fundamentales de la relatividad general, incluyendo algunos antecedentes históricos. Se describe el funcionamiento básico de los detectores, como así también características principales de su construcción. Presentamos un estudio preliminar de la señal detectada en septiembre de 2015 por los observatorios de ondas gravitacionales LIGO.; We present a brief description on the first detection of gravitational waves. We take the opportunity to comment on fundamental aspects of general relativity, including some historical remarks. The basic operation of the gravitational wave detectors is presented, along with the main characteristics of its construction. We present a preliminary study of the signal detected on September of 2015 by the LIGO observatories of gravitational waves.

P-Sulfonic acid calix[4]arene-functionalized alkyl-bridged organosilica in esterification reactions De Assis, J. V.; Abranches, P. A. S.; Braga, I. B.; Portilla Zúñiga, Omar Miguel; Sathicq, Angel Gabriel; Romanelli, Gustavo Pablo; Sato, A. G.; Fernandes, S. A. Two new p-sulfonic acid calix[4]arene- and p-sulfonic acid calix[6]arene-functionalized organosilica have been synthesized using a sol-gel method and applied as heterogeneous catalysts in esterification reactions. The catalytic performance was evaluated using the esterification of carboxylic acids with ethanol, and good catalytic activity (i.e., 55-88%) was observed under the optimum reaction conditions. This study reports the first promising example of the successful employment of calix[n]arenes as a heterogeneous catalyst for catalytic esterification. The catalyst was easily separated by filtration and reused five times without any significant loss of activity.

Lógica de la gestión ambientalmente adecuada y patrón de desarrollo sustentable en América Latina: el tema emblemático de las políticas de residuos peligrosos en Argentina en los años 90; Logics of environmentally adequate management and the sustainable development pattern: the emblematic issue of the hazardous waste policies in Argentina in the 90´s Foa Torres, Jorge Gabriel Este trabajo presenta un análisis político-discursivo del proceso de ecologización experimentado por los mercados y Estados latinoamericanos durante la década de los 90 a través del estudio del tema emblemático de las políticas de gestión ambientalmente adecuada de residuos peligrosos en Argentina. La perspectiva en la que se inscribe este artículo es la del análisis posmarxista de políticas que busca poner énfasis en los momentos fundacionales de los procesos de significación implicados en las políticas públicas. Para la comprensión y crítica de tal proceso de ecologización, se identificó a la lógica de la gestión ambientalmente adecuada como categoría que permitió condensar un cúmulo de prácticas discursivas orientadas a: reducir al Estado a mero gestor del mercado, autorrestringir sus atribuciones soberanas y limitar su tarea en torno a los residuos peligrosos a la función registral en pos de favorecer a las estrategias de autocontrol empresarial. La explicación del problema de investigación construida a partir de la lógica de la gestión ambientalmente adecuada dio lugar, a su vez, a la identificación de una hipótesis explicativa central del proceso de ecologización de los años 90 en Argentina y América Latina: al desarrollo sustentable en tanto patrón de desarrollo y referencia de sentido central en la década a la hora de significar a los problemas ambientales y sus soluciones más adecuadas. La idea de patrón implica, en este caso, antes que cualquier pretendida intervención humanitaria-ecológica internacional para la protección técnica del entorno natural, la vía más adecuada para, por un lado, la radicalización de las condiciones estructuralmente heterogéneas de una economía periférica como la Argentina y, por otro, la profundización de las asimetrías entre los países del Norte y los del Sur así como también la transnacionalización del aparato productivo nacional.; This article presents a discursive-political analysis of the greening process experienced by the markets and Latin American States during the 90’s through the study of the emblematic issue of the environmentally sound management policies of hazardous waste in Argentina. The perspective of this article is the post-Marxist analysis of policies that seeks to put emphasis on the founding moments of significant processes involved in public policies. To understand and critique such greening process, it was necessary to identify the logic of the adequate environmentally sound management as a category that allowed condensing a cluster of discursive practices aimed at: reducing the State to mere market operator, self-restrict its sovereign powers, and limit its work around hazardous waste to the information recording function towards favoring strategies of business self-control. The explanation of the research problem constructed from the logic of the environmentally sound management led, in turn, to the identification of a central explanatory hypothesis of the greening process in the 90’s in Argentina and Latin America: sustainable development as development pattern and central reference point in the decade when it comes to signify environmental problems and their most adequate solutions. The idea of pattern implies in this case, rather than any supposed international humanitarian-ecological intervention for the technical protection of the natural environment, the most adequate, on one hand, for the radicalization of structurally heterogeneous conditions of peripheral economy such as the Argentinian economy and, on the other hand, to go deeper into the asymmetries between the North and South countries as well as the transnationalism of the national productive.

Identification of G protein coupled receptors for opsines and neurohormones in Rhodnius prolixus. Genomic and transcriptomic analysis Ons, Sheila; Lavore, Andres Esteban; Sterkel, Marcos; Wulff, Juan Pedro; Sierra, Ivana Samanta; Martínez Barnetche, Jesús; Rodriguez, Mario Henry; Rivera Pomar, Rolando The importance of Chagas disease motivated the scientific effort to obtain the complete genomic sequence of the vector species Rhodnius prolixus, this information is also relevant to the understanding of triatomine biology in general. The central nervous system is the key regulator of insect physiology and behavior. Neurohormones (neuropeptides and biogenic amines) are the chemical messengers involved in the regulation and integration of neuroendocrine signals. In insects, this signaling is mainly mediated by the interaction of neurohormone ligands with G protein coupled receptors (GPCRs). The recently sequenced R. prolixus genome provides us with the opportunity to analyze this important family of genes in triatomines, supplying relevant information for further functional studies. Next-generation sequencing methods offer an excellent opportunity for transcriptomic exploration in key organs and tissues in the presence of a reference genome as well as when a reference genome is not available. We undertook a genomic analysis to obtain a genome-wide inventory of opsines and the GPCRs for neurohormones in R. prolixus. Furthermore, we performed a transcriptomic analysis of R. prolixus central nervous system, focusing on neuropeptide precursor genes and neurohormone and opsines GPCRs. In addition, we mined the whole transcriptomes of Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis - three sanitary relevant triatomine species - to identify neuropeptide precursors and GPCRs genes. Our study reveals a high degree of sequence conservation in the molecular components of the neuroendocrine system of triatomines.

Inhibitory effect and cell damage on bacterial flora of fish caused by chitosan, nisin and sodium lactate Schelegueda, Laura Inés; Zalazar, Aldana Lourdes; Gliemmo, María Fernanda; Campos, Carmen Adriana The effect of the combined use of chitosan, nisin and sodium lactate on the growth of Listeria innocua, Shewanella putrefaciens and psychrophilic bacteria isolated from fish was investigated in broth by means of minimum inhibitory concentrations (MIC). Furthermore, the sites of cell-injury caused by mentioned antimicrobials and their combinations on L. innocua and S. putrefaciens were studied. MIC of antimicrobial mixtures were evaluated by Berembaum design and check board method. Antimicrobials' sites of injury were investigated by the evaluation of cell constituents' release, cell surface hydrophobicity and differential scanning calorimetry. Results depended on antimicrobial used; several combinations inhibited the growth of L. innocua and S. putrefaciens and all combinations inhibited psychrophilic bacteria. Besides, some mixtures showed synergistic effects. All the mixtures affected ribosomes and DNA of the studied bacteria. Regarding cellular envelope, antimicrobials acted according to the structural characteristics of target microorganisms. Cell damage was higher when antimicrobials were combined, which could explain the observed synergistic effects. This study demonstrates and justifies the synergistic action of chitosan, nisin and sodium lactate on the inhibition of microorganisms related to fish spoilage and remarks the promissory use of the synergic combination of antimicrobials for fish preservation.