Abundance of the quorum-sensing factor Ax21 in four strains of Stenotrophomonas maltophilia correlates with mortality rate in a new zebrafish model of infection Ferrer Navarro, Mario; Planell, Raquel; Yero, Daniel; Mongiardini, Elias Javier; Torrent, Gerard; Huedo, Pol; Martinez, Paula; Roher, Nerea; Mackenzie, Simon; Gibert, Isidre; Daura, Xavier Stenotrophomonas maltophilia is a Gram-negative pathogen with emerging nosocomial incidence. Little is known about its pathogenesis and the genomic diversity exhibited by clinical isolates complicates the study of pathogenicity and virulence factors. Here, we present a strategy to identify such factors in new clinical isolates of S. maltophilia, incorporating an adultzebrafish model of S. maltophilia infection to evaluate relative virulence coupled to 2D difference gel electrophoresis to explore underlying differences in protein expression. In this study we report upon three recent clinical isolates and use the collection strain ATCC13637 as a reference. The adult-zebrafish model shows discrimination capacity, i.e. from very low to very high mortality rates, with clinical symptoms very similar to those observed in natural S. maltophilia infections in fish. Strain virulence correlates with resistance to human serum, in agreement with previous studies in mouse and rat and therefore supporting zebrafish as a replacement model. Despite its clinical origin, the collection strain ATCC13637 showed obvious signs of attenuation in zebrafish, with null mortality. Multilocus-sequence-typing analysis revealed that the most virulent strains, UV74 and M30, exhibit the strongest genetic similitude. Differential proteomic analysis led to the identification of 38 proteins with significantly different abundance in the three clinical strains relative to the reference strain. Orthologs of several of these proteins have been already reported to have a role in pathogenesis, virulence or resistance mechanisms thus supporting our strategy. Proof of concept is further provided by protein Ax21, whose abundance is shown here to be directly proportional to mortality in the zebrafish infection model. Indeed, recent studies have demonstrated that this protein is a quorum-sensing-related virulence factor.

Resveratrol modulates ATPase activity of liposome-reconstituted ABCG1 de Athayde Moncovo Collado, Alejandro; Corbalan, Natalia Soledad; Homolya, László; Morero, Roberto Dionisio; Minahk, Carlos Javier ABCG1 is a half-sized transporter with an unquestionable importance in cholesterol homeostasis. So far, its expression and thus its activity was suggested to be regulated at transcriptional level by LXR and PPAR agonists including polyphenols. However, it is unknown whether there are other mechanisms of up-regulation of ABCG1 activity. In the present work resveratrol was shown to induce a nearly twofold increase in ATPase activity of reconstituted ABCG1. Evidence is presented for the first time suggesting that resveratrol is able to activate ABCG1 activity by an alternative mechanism that involves an indirect interaction.

Icnología de la formación Río Mayer, Cretácico inferior, Sudoeste de Gondwana, Patagonia, Argentina; Ichnology of the Río Mayer formation, Lower Cretaceous, Southwestern Gondwana, Patagonia, Argentina Richiano, Sebastián Miguel; Poire, Daniel Gustavo; Varela, Augusto Nicolás The Río Mayer Formation was deposited during the Early Cretaceous in the Austral Basin (Santa Cruz Province, Argentina) and includes black shales with intercalated sandstones and marls. Abundant information is available on its palaeontological content, especially on ammonoids, but detailed ichnological studies are lacking. Sedimentological and ichnological data were collected in the Río Guanaco area (49°57′11″S—72°04′56″W). Three sections were identified and described in detail. The lower Section was deposited during the Berriasian—Valanginian and is composed of black shales. The middle section including black marls with intercalated black shales was deposited during the Valanginian—Hauterivian. The upper section is composed of black shales with frequent thin intercalations of finegrained sandstones (Barremian—Albian). Six ichnogenera were identified: Zoophycos, Chondrites, Bergaueria, Ophiomorpha, Palaeophycus and Teredolites. The most abundant and constant is Zoophycos, arranged in three morphological groups. All these ichnogenera are grouped —in the Río Mayer Formation— into two ichnoassociations. The first is found in the middle section, and is a typical Zoophycos ichnofacies with associated Bergaueria. The second ichnoassociation appears at the top of the upper section, and contains a Zoophycos ichnofacies with associated Ophiomorpha and Teredolites. The unusual presence of Bergaueria in low oxygen offshore environments, exceeds the bathymetric range typical of this ichnogenus. The unusual presence of O. cf. rudis in outer shelf environments reveals the existence of doomed pioneers in the analyzed unit.; La Formación Río Mayer, compuesta principalmente por pelitas negras con intercalaciones de areniscas y margas, se depositó en la Cuenca Austral (Provincia de Santa Cruz, Argentina) durante el Cretácico Temprano. Existe abundante información en cuanto al contenido fósil, en especial amonites, pero se carece de estudios icnológicos y es este trabajo el primero enfocado en este tópico. En la región de Río Guanaco (49°57′11″S—72°04′56″O), a partir de un relevamiento sedimentológico e icnológico se diferenciaron tres secciones. La sección inferior (Berriasiano—Valanginiano) se compone casi enteramente de pelitas negras. La sección media (Valanginiano—Hauteriviano) posee un predominio de margas, mientras que en la superior (Barremiano—Albiano) dominan las pelitas con intercalaciones arenosas. Se reconocieron seis icnogéneros: Zoophycos, Chondrites, Bergaueria, Ophiomorpha, Palaeophycus y Teredolites. Zoophycos es el icnogénero más abundante y constante, y se lo dividió en 3 grupos morfológicos. Se reconocen dos icnoasociaciones. Una se corresponde con la sección media incluyendo una icnofacies de Zoophycos con Bergaueria asociada. La otra se desarrolla en la sección superior y posee también una icnofacies de Zoophycos, pero en este caso asociada a ejemplares de Ophiomorpha y Teredolites. En ambientes de costa afuera con baja oxigenación se registra un hallazgo poco usual de Bergaueria, excediendo el rango batimétrico típico del icnogénero. Se documenta la presencia inusual de O. cf. rudis en ambientes de plataforma externa, lo cual confirma la existencia de colonizadores condenados (doomed pioneers) en la unidad estudiada.

La imposibilidad de un ejército profesional: Ramón de Cáceres y el establecimiento de procedimientos burocráticos en las fuerzas del Río de la Plata. 1810-1830; The impossibility of a professional army: Ramón de Cáceres and the establishment of bureaucratic procedures in the River Plate military forces. 1810-1830 Rabinovich, Alejandro Martín El presente artículo aborda la problemática de la profesionalización de las fuerzas militares del Estado rioplatense independiente a partir de un ángulo muy poco analizado hasta hoy: los intentos de establecer procedimientos burocráticos y un tipo particular de disciplina en el seno de unidades combatientes surgidas de una intensa movilización popular. Primero se analizarán las reglamentaciones que regían la administración de los ejércitos, con especial énfasis en la descripción del tipo de funcionariado que era buscado por los modelos europeos de la época. Luego, este deber ser de la administración militar será confrontado con el estudio de un caso puntual: el traumático intento de transformación de los Dragones Libertadores -surgidos del alzamiento de la campaña oriental en 1825- en Regimiento de Caballería de Línea, ocurrido en el seno del Ejército Republicano que se aprestaba para abrir la guerra con el Brasil. Este modesto episodio, explorado a través de las memorias personales del oficial a cargo de llevar adelante la reforma del cuerpo, nos permitirá echar luz sobre las limitaciones concretas encontradas en el terreno por aquellos funcionarios que hablaban en nombre del Estado y pretendían someter a las fuerzas de un pueblo en armas a una lógica procedimental-formal.; This paper addresses the problem of the professionalization of the military forces of the River Plate state in the first half of the 19th century, analyzing the attempts to establish a particular type of discipline and bureaucratic procedures in combat units that had emerged from a very intense popular mobilization. This problem is studied in two times. The regulations governing the administration of the armies and the kind of administrative tasks that were demanded from each officer will first be analyzed. Then this ideal administrative model imported from Europe will be confronted with the realities of its application, through the study of a particular case: the traumatic attempt to transform the Freedom Dragoons -a unit born from the Banda Oriental rural uprising of 1825- into a Line Cavalry Regiment within the Republican Army which was about to open the war against the Brazil. This modest episode, explored through the memoirs of the officer in charge of the reform, will enable us to shed light on the specific constraints encountered by those officials who spoke on behalf of the State and intended to discipline the forces of a people in arms.

Evaluación de indicadores metabólicos y bioquímicos sanguíneos en vacas en lactancia con Enfermedad Quística Ovárica; Evaluation of metabolic and biochemical blood parameters in lactating cows with Cystic Ovarian Disease Cattaneo, L.; Barberis, F. C.; Stangaferro, M. L.; Signorini Porchietto, Marcelo Lisandro; Ruiz, Marcelo Fabián; Zimmermann, R.; Bo, Gabriel Amilcar; Hein, Gustavo Juan; Ortega, Hugo Hector El objetivo de este trabajo fue determinar y evaluar indicadores bioquímicos sanguíneos asociados a procesos metabólicos energéticos, proteicos, minerales y de funcionalidad hepática, junto con parámetros productivos y reproductivos en vacas lecheras que fueron diagnosticadas con enfermedad quística ovárica (COD) y controles. Se emplearon vacas Holando Argentino en lactancia de 5 rebaños de la provincia de Santa Fe (Argentina) que presentaban COD (n= 80) diagnosticada mediante ultrasonografía y controles clínicamente sanas (n= 124). De las vacas se obtuvo sangre coccígea para determinar las concentraciones séricas de las hormonas de crecimiento (GH), factor de crecimiento similar a la insulina-1 (IGF-1) e insulina, la actividad sérica de AST, FA, GGT y las concentraciones séricas de albúmina, proteínas totales, relación albúmina: globulinas, Bilirrubina total y directa, β-hidroxibutirato, colesterol, glucosa, urea, creatinina, calcio, fósforo y magnesio. Las concentraciones séricas de insulina e IGF-1 fueron menores (P<0,05) en las vacas con COD que en las controles. No se observaron diferencias significativas (P>0,05) entre ambos grupos en las demás variables séricas y productivas evaluadas, sin embargo, el intervalo parto-concepción fue mayor en vacas que presentaron COD. Los resultados nos permitieron concluir que habría una asociación entre los valores séricos de IGF-1 e insulina y la COD, y que ésta comprometería el futuro reproductivo de las vacas.; The aim of the study was to determine and evaluate different blood parameters associated to energetic, protein, mineral and liver metabolic processes together with productive and reproductive parameters in dairy cows of Santa Fe province (Argentina) that were diagnosed with cystic ovarian disease (COD). Lactating Argentine Holstein cows from five dairy herds with spontaneous COD (n= 80) diagnosed by ultrasound and control cows (n= 124) were included in the study. Blood samples were obtained from all cows to determine serum concentrations of: growth hormone, insulin-like growth factor (IGF-1), insulin, aspartate aminotransferase, alkalin phosphatase, gamma glutamiltransferase, albumin, total proteins, albumin: globulin ratio, total and direct bilirrubin, β-hidroxibutirate, colesterol, glucose, urea, creatinin, calcium, phosphorus and magnesium. Serum concentrations of insulin and IGF-1 were lower (P<0.05) in COD than control cows. No significant differences among groups were observed in any other variables studied, however, the calving to conception interval was higher in cows with COD compared to controls. These results allowed us to conclude that there would be an association between blood concentrations of IGF-1 and insulin and COD that, ultimately, compromise the reproductive performance of the cow.

Interleukin-10 controls human peripheral PMN activation triggered by lipopolysaccharide Martire Greco, Daiana; Rodriguez Rodrigues, Nahuel Emiliano; Landoni, Verónica Inés; Rearte, María Bárbara; Isturiz, Martín Amadeo; Fernández, Gabriela Cristina Large amounts of anti-inflammatory mediators, such as interleukin (IL)-10, are produced and found early in the course of sepsis. We explore the role of IL-10 on neutrophil (PMN) activation/function using an in vitro model. Isolated human PMN were pre-incubated with polysaccharide (LPS) and/or IL-10 for 18 h. Subsequently, a second LPS exposure was performed and CD11b and CD66b up-regulation, and the reactive oxygen species (ROS) generation were measured 2 h later. We found that IL-10 prevented PMN activation and the secretion of TNF-a and IL-8 induced by the first LPS contact. In the absence of IL-10, a second LPS exposure induced additive effects that were prevented by IL-10. Only ROS generation was highly affected by the blockade of PMN-secreted TNF-a or IL-8. Additionally, IL-10 prevented other possible mechanisms of LPS priming. Therefore, IL-10 modulates PMN activation preventing autocrine activating loops and priming mechanisms, rendering PMN less responsive to a second LPS exposure.

Hidrología isotópica: herramienta nuclear en apoyo a la conservación de los recursos hídricos en la subcuenca Artemisa-Quivicán; Isotopic hydrology: nuclear tool to support the conservation of water resources in the Artemisa-Quivicán sub-basin Peralta Vital, José Luis; Gil Castillo, Reinaldo; Fleitas Estévez, Gelma Gretel; Dapeña, Cristina; Valdés González, Lourdes Se caracterizó el acuífero de la subcuenca subterránea costera Artemisa-Quivicán, mediante el uso de las técnicas nucleares (hidrología isotópica), con el objetivo de proponer su mejor explotación y contribuir a la gestión sostenible de los recursos hídricos en la s provincias de Artemisa, Mayabeque y La Habana (Cuba). Fueron desarrolladas cuatro etapas, que incluyeron el diseño y definición de la red optimizada para el monitoreo isotópico y físico-químico en el agua subterránea y superficial, la caracterización isotópica y físico-química de las aguas y las precipitaciones en la región, la identificación de las posibles fuentes de contaminación y la obtención de criterios isotópicos y físico-químicos para evaluar la vulnerabilidad a la contaminación en la subcuenca. Los resultados apoyaron la resolución eficaz de los problemas ambientales de la gestión sostenible de los recursos hídricos de la cuenca, los cuales sustentan la producción de alimentos de las provincias involucradas, además de aportar el agua para su consumo.; The aquifer of the coastal underground sub -Basin "Artemisa-Quivicán" was characterized by means of nuclear techniques (isotopic hydrology), in order to propose its best exploitation and contribute to the sustainable management of the water resources in the involved provinces. Four investigative stages were developed, which included the design and definition of the net optimized for isotopic and physiochemical monitoring in underground and surface waters; the isotopic and physical -chemistry characterization of waters and precipitations in the region; the identification of the possible co ntamination sources; and finally the obtaining of isotopic and physical-chemical criteria to evaluate the vulnerability to the contamination in the sub -basin. The results supported the effective solution of the environmental problems related to the sustainable management of hydrological resources in the basin. Such water resources sustain food production in the area and contribute to the water consumption.

Extreme densities in Titan's ionosphere during the T85 magnetosheath encounter Edberg, N. J. T.; Andrews, D. J.; Shebanits, O.; Agren, K.; Wahlund, J. E.; Opgenoorth, H. J.; Roussos, E.; Garnier, P.; Cravens, T. E.; Badman, S. V.; Modolo, R.; Bertucci, Cesar; Dougherty, M. K. We present Cassini Langmuir probe measurements of the highest electron number densities ever reported from the ionosphere of Titan. The measured density reached 4310 cm−3 during the T85 Titan flyby. This is at least 500 cm−3 higher than ever observed before and at least 50% above the average density for similar solar zenith angles. The peak of the ionospheric density is not reached on this flyby, making the maximum measured density a lower limit. During this flyby, we also report that an impacting coronal mass ejection (CME) leaves Titan in the magnetosheath of Saturn, where it is exposed to shocked solar wind plasma for at least 2 h 45 min. We suggest that the solar wind plasma in the magnetosheath during the CME conditions significantly modifies Titan's ionosphere by an addition of particle impact ionization by precipitating protons.

Caracterización petrográfica de cerámicas santamarianas e inkas procedentes del sitio arqueológico Fuerte Quemado-Intihuatana, provincia de Catamarca Orgaz, Martín A.; de la Fuente, Guillermo Adrian En este trabajo se presentan los resultados obtenidos a través de la caracterización petrográfica de una muestra de fragmentos cerámicos (N=37) procedentes del sitio arqueológico Fuerte Quemado-Intihuatana. El sitio Fuerte QuemadoIntihuatana es una instalación Santamariano que presenta una ocupación Inkaica en algunos sectores específicos. La cerámica pertenece a momentos del Período de Desarrollos Regionales (ca. AD 900 – AD 1450) e Inka (ca. AD 1480 – AD 1532). Los resultados obtenidos indican la presencia de elecciones tecnológicas diferentes observadas en las recetas utilizadas por los alfareros para manufacturar la cerámica durante estos dos momentos prehispánicos del NOA.; In this paper, we present the results obtained through a petrographic characterization on a ceramic sample (N=37) from Fuerte Quemado archaeological site. The site Fuerte Quemado belongs to Santamaria Culture, and it presents a unique Inka occupation in some specific sectors. Ceramics analysed are from Late (ca. AD 900 - AD 1450) and Inka (ca. AD 1480 – AD 1532) periods. Results obtained indicate the presence of different technological choices for these two prehispanic times, observed in the paste recipes utilized by ancient potters for the manufacture of ceramic vessels.

Ambientes urbanos como refugios del Cuervillo cara pelada (Phimosus infuscatus) ante el déficit hídrico transitorio; Urban environments as refuge of bare-faced IBIS (Phimosus infuscatus) under water stress period Acosta, Tamara Hilén; Dadon, Jose Roberto Se presentan registros del Cuervillo Cara Pelada (Phimosus infuscatus) en un núcleo turístico urbano de la provincia de Buenos Aires. Los individuos fueron identificados en sectores de jardines privados, bajo un régimen de riego anual. Las observaciones coincidieron con un período de déficit hídrico para la región. La existencia de este tipo de urbanizaciones podría favorecer también a otras especies bajo condiciones ambientales desfavorables. La presencia de especies como Phimosus infuscatus podrían ser consideradas como indicadores del estado de áreas con humedales y para información complementaria de sistemas de alerta temprana.; Records of Bare-faced Ibis (Phimosus infuscatus) were taken in a coastal beach resort in Buenos Aires province. Individuals were identified in front garden areas, under a system of annual irrigation. Observations coincided with a water stress period in the region. This kind of urban settlement could also help other species under unfavorable environmental conditions. The presence of species such as Phimosus infuscatus could be considered as a biological indicator of wetland state and as data for developing early warning systems.

Seasonal variation and effect of non-native invasive vegetation on two bird communities in northeast of Buenos Aires province, Argentina; Variación estacional y efecto de vegetación exótica invasora sobre dos comunidades de aves en el noreste de la provincia de Buenos Aires, Argentina Palacio, Facundo Xavier; Montalti, Diego We studied seasonal patterns and the effect of non-native invasive vegetation on bird communities in woodland and adjacent herbaceous-shrub areas in north-east Buenos Aires province, Argentina. Diversity, species richness and density of bird species were higher in spring and summer than in fall and winter in both habitat types. We also found significant between-habitat differences in bird species composition in winter, spring and summer. Seasonal variations were mainly due to changes in the abundance of migrants, whereas bird species segregation to each habitat was mostly explained by non-native vegetation structure. Most species were associated with sites dominated by either Dipsacus fullonum or Gleditsia triacanthos, whereas only four species were associated with high Ligustrum lucidum densities. These results show that despite the dominance of non-native invasive plant species at our study site, vegetation structure is still the main factor structuring bird communities. In addition, some plant species, such as L. lucidum, seem to have a negative effect on bird communities by reducing their diversity, whereas others, such as D. fullonum and G. triacanthos, seem to have a positive effect compared to L. lucidum by providing not only food resources during a great part of the year but also nest sites.; Estudiamos los patrones estacionales y el efecto de vegetación exótica invasora en comunidades de aves de bosque y zonas herbá- ceo-arbustivas adyacentes en el noreste de la provincia de Buenos Aires, Argentina. Diversidad, riqueza y densidad de aves fueron mayores en primavera-verano que en otoño-invierno en ambos tipos de ambiente. Además, encontramos diferencias significativas entre hábitats en la composición de especies en invierno, primavera y verano. Las variaciones estacionales en los atributos comunitarios se debieron principalmente a cambios en la abundancia de aves migratorias, mientras que la segregación de especies en ambos ambientes estuvo explicada en gran parte por la estructura de la vegetación de especies exóticas invasoras. La gran mayoría de las especies de aves estuvieron asociadas a sitios dominados por Dipsacus fullonum ó Gleditsia triacanthos, mientras que sólo cuatro especies estuvieron asociadas a sitios con altas densidades de Ligustrum lucidum. Nuestros resultados muestran que a pesar de la dominancia de vegetación exótica invasora en nuestro sitio de estudio, la estructura de la vegetación es el principal factor que estructura las comunidades de aves. Asimismo, algunas especies exóticas, como L. lucidum, tendrían un efecto negativo sobre las comunidades de aves al disminuir su diversidad, mientras que otras, como D. fullonum y G. triacanthos, tendrían un efecto positivo en comparación con L. lucidum al proveer no solo alimento durante gran parte del año, sino también sitios de nidificación.

Effectiveness of fluoxetine to control fur-chewing behaviour in the chinchilla (Chinchilla lanigera) Galeano, Maria G.; Ruiz, Ruben Daniel; Fiol de Cuneo, Marta; Ponzio, Marina Flavia Due to its complexity and the relative lack of scientific reports, fur-chewing may be considered as one of the most challenging behavioural problems common to captive chinchillas. The development of this behaviour in commercial farms and the increasing popularity of this species as a pet have increased the public demands for a treatment. The objective of this work was to evaluate the effectiveness of fluoxetine to control the development of chinchillas’ fur-chewing behaviour, using an oral dose of 10 mg/kg/day for a 90 days treatment period. For the measurement of the fur-chewing affected area and its variation during treatment as external sign of whether or not the behaviour was controlled, digital pictures were taken at 0, 45, 75 and 90 days of treatment and after drug withdrawal at 140 days. Results indicated that the greatest difference in percentages of body area affected by the behaviour in control vs. treated animals was observed after 75 days of treatment. However, this was not due to a decrease in the amount of body area affected by fur-chewing in treated animals, but conversely to an increase in the symptoms observed in control animals, that showed a ~10% increase in the fur-chewing affected body area than at the beginning of the experiments. Only ~46% of the fluoxetine treated animals showed a significant reduction in the body area affected by fur-chewing. In summary, the use of fluoxetine in fur-chewing chinchillas showed limited success, mostly reducing the progression of the behaviour.

Determinations of gas–liquid partition coefficients using capillary chromatographic columns. Alkanols in squalane Tascon, Marcos; Romero, Lilian M.; Acquaviva, Agustín; Keunchkarian, Sonia; Castells, Cecilia Beatriz Marta This study focused on an investigation into the experimental quantities inherent in the determination of partition coefficients from gas–liquid chromatographic measurements through the use of capillary columns.Wepreparedseveral squalane – (2,6,10,15,19,23-hexamethyltetracosane) – containing columns with very precisely known phase ratios and determined solute retention and hold-up times at 30, 40, 50 and 60 ◦C. We calculated infinite dilution partition coefficients from the slopes of the linear regression of retention factors as a function of the reciprocal of the phase ratio by means of fundamental chromatographic equations. In order to minimize gas–solid and liquid–solid interface contributions to retention, the surface of the capillary inner wall was pretreated to guarantee a uniform coat of stationary phase. The validity of the proposed approach was first tested by estimating the partition coefficients of n-alkanes between n-pentane and n-nonane, for which compounds data from the literature were available. Then partition coefficients of sixteen aliphatic alcohols in squalane were determined at those four temperatures. We deliberately chose these highly challenging systems: alcohols in the reference paraf- finic stationary phase. These solutes exhibited adsorption in the gas–liquid interface that contributed to retention. The corresponding adsorption constant values were estimated.We fully discuss here the uncertainties associated with each experimental measurement and how these fundamental determinations can be performed precisely by circumventing the main drawbacks. The proposed strategy is reliable andmuchsimpler thanthe classical chromatographicmethod employing packed columns.

Effect of buffer systems and disaccharides concentration on Podoviridae coliphage stability during freeze drying and storage Dini, Cecilia; De Urraza, Patricio José The aims of this study were to determine the stability of Podoviridae coliphage CA933P during lyophilization and storage in different media, and to establish similarities between the results obtained and those expected through mechanisms described for proteins stabilization during freeze-drying. PBS and SM buffer were assayed as lyophilization media. The effect of inorganic salts concentration as well as the addition of disaccharides on phage stability during freeze-drying and storage was also studied. The addition of low suc rose concentration (0.1 mol l1 ) to SM buffer stabilized phage during freezing and dryi ng steps of the lyophilization process, but higher sugar concentrations were detriment al to phage stability during freeze-drying. Sucrose stabilized phage during storage for at least 120 days. The lyoprotective effect of low concentrations of disaccharides during the drying step of the lyophilization of proteins as well as the stabilization of the freeze-dried produc t in time correlated with the results obtained for phage CA933P.

Mathematical Modeling of Bivariate Distributions of Polymer Properties Using 2D Probability Generating Functions. Part II: Transformation of Population Mass Balances of Polymer Processes Brandolin, Adriana; Asteasuain, Mariano This is the second of two works presenting a new mathematical method for modeling bivariate distributions of polymer properties. It is based on the transformation of population balances using 2D probability generating functions (pgf) and a posteriori recovery of the distribution from the transform domain by numerical inversion. Part I of this work was devoted to the numerical inversion step. Here the transformation of the population balances to the pgf domain is analyzed. A 2D pgf transform table is developed, which allows a simple transformation of any typical polymer balance equation. Three copolymerization examples are used to show the application of the complete procedure of this modeling technique.

Physical Properties of Aqueous Solutions of Pectin Containing Sunflower Wax Baumler, Erica Raquel; Carelli Albarracin, Amalia Antonia; Martini, Silvana The aim of this study is to investigate the physical properties of aqueous solutions of pectin (PA) containing sunflower wax (SFW), which are used as a basis for producing edible films. The stability and the rheological and microstructural characteristics of SFW/PA mixtures were evaluated. SFW/PA mixtures formed oil-in-water emulsions that were milky and opaque in appearance and were stable towards phase separation. Polarized micrographs revealed the presence of wax crystals, whose size decreased as pectin concentration increased. The rheological behavior of the aqueous solutions of pectin containing different amounts of SFW were best described by the generalized power law model of Herschel-Bulkley (H-B), which gave the best fit in all the range of shear rate values. Apparent viscosities and yield stress were determined using this model, and both properties increased with increasing pectin content. The apparent viscosity values were between 0.0095 and 0.1031 Pa s. SFW addition resulted in a small decrease in viscosity for emulsions formulated with 1 and 2 % PA, but the opposite effect was observed for emulsions formulated with 3 % PA. In addition, shear stress values were higher for emulsions with higher PA content, but were not affected by SFW addition.

Delocalized and localized states of eg electrons in half-doped manganites Winkler, Elin Lilian; Tovar, Manuel; Causa, M. T. We have studied the magnetic behaviour of half-doped manganite Y0.5Ca0.5MnO3 in an extended range of temperatures by means of magnetic susceptibility and electron spin resonance (ESR) experiments. At high temperature the system crystallizes in an orthorhombic structure. The resistivity value ~0:05 Ohm.cm at 500 K, indicates a metallic behaviour, while the Curie-Weiss dependence of the susceptivility and the thermal evolution of the ESR parameters are very well described by a model that considers a system conformed by localized Mn4+ cores,t2g^3, and itinerant, eg, electrons. The strong coupling between t2g and eg electrons results in an enhanced Curie constant and an FM Curie-Weiss temperature that overcomes the AFM interactions between the t2g^3 cores. A transition to a more distorted phase is observed at T ~500 K and signatures of localization of the eg electrons appear in the susceptibility behaviour below 300 K. A new Curie-Weiss regime is observed, where the Curie-constant value is consistent with dimer formation. Based on mean-field calculations, the dimer formation predicted as a function of the interaction strength between the t2g and eg electrons.

Notas sobre el desarrollo del conocimiento técnico aplicado en los procesos de trabajo.; Notes on the development of knowledge “technical” applied in work processes Cristobo, Matias Este artículo se propone reflexionar sobre el carácter ideológico de la ciencia y la técnica analizado por Herbert Marcuse y Jürgen Habermas a partir de una lectura de la obra de Marx. La discusión entre los dos primeros autores incluye categorías y problemáticas fundamentales para la tradición marxista: desarrollo de las fuerzas productivas, relaciones de producción, proletariado como sujeto revolucionario, intervención del Estado en la regulación de los procesos económicos, etc. Pero la discusión precedente también incluye una interpretación sobre el devenir de la ciencia y la técnica convertidas de inmediato en una fuerza productiva. Voy a detenerme en mi trabajo sobre este punto en particular. En primer lugar, me propongo exponer y analizar la propia posición de Marx referida al tema, presente en forma condensada en la sección de los Elementos Fundamentales para la Crítica de la Economía Política [Grundrisse] vinculada al desarrollo del capital fijo (y maquinaria). En segundo lugar, me detendré en las dos lecturas propuestas por Marcuse y Habermas que parten, precisamente, del mismo pasaje de los Grundrisse. Finalmente, intentaré exponer brevemente las similitudes y diferencias que suponen los planteos aquí tratados.; This article aims to reflect on the character "ideology" of science and technology discussed by Herbert Marcuse and Jürgen Habermas from a reading of Marx's work. The discussion between the first two categories and authors include fundamental issues for the Marxist tradition: development of productive forces, relations of production, the proletariat as revolutionary subject, state intervention in the regulation of economic processes, etc.. But the preceding discussion also includes an interpretation of the future of science and technology immediately converted into a productive force. I will focus on my work on this particular point. First, I propose to present and analyze Marx's own position relating to the subject, in condensed form in this section of the key elements to the Critique of Political Economy [Grundrisse] linked to the development of fixed capital (and machinery). Second, I will consider the two readings proposed by Marcuse and Habermas departing precisely the same passage from the Grundrisse. Eventually we briefly outline the similarities and differences that pose the proposals discussed here.

Novel interactions of GRP78: UPR and estrogen responses in the brain Avila, Marco Fidel; Cabezas, Ricardo; Torrente, Daniel; Gonzalez, Janneth; Morales, Ludis; Alvarez, Lisandro; Capani, Francisco; Barreto, George E. Glucose-regulated protein 78 (GRP78; 78 kDa) belongs to a group of highly conserved heat shock proteins (Hsp) with important functions at the cellular level. The emerging interest for GRP78 relies on its different functions, both in normal and pathological circumstances. GRP78 regulates intracellular calcium, protein shaping, endoplasmic reticulum (ER) stress and cell survival by an immediate response to insults, and that its expression may also be regulated by estrogens. Although these roles are well explored, the mechanisms by which GRP78 induces these changes are not completely understood. In this review, we highlight various aspects related to the GRP78 functioning in cellular protection and repair in response to ER stress and unfolded protein response by the regulation of intracellular Ca2+ and other mechanisms. In this respect, the novel interactions between GRP78 and estrogens, such as estradiol and others, are analyzed in the context of the central nervous system (CNS). We also discuss the importance of GRP78 and estrogens in brain diseases including ischemia, Alzheimer's and Huntington's disorders. Finally, the main protective mechanisms of GRP78 and estrogens during ER dysfunction in the brain are described, and the prospective roles of GRP78 in therapeutic processes.

Vacuna terapéutica CSF-470 para melanoma cutáneo Aris, Mariana; Barrio, Maria Marcela; Mordoh, Jose El melanoma cutáneo es la patología tumoral con mayor incidencia de crecimiento. Una vez que hace metástasis, es resistente a los tratamientos convencionales, con pronóstico reservado. Recientemente han surgido nuevas estrategias terapéuticas con resultados alentadores, incluyendo la inmunoterapia. En esta nota nos centraremos en el uso de vacunas, en particular en la vacuna alogeneica irradiada CSF-470, coadyuvada con BCG y Molgramostim (GM-CSF), para el tratamiento adyuvante de pacientes con melanoma cutáneo estadios IIB, IIC o III post-cirugía. Describiremos los resultados del estudio clínico de fase I y el diseño del estudio actual de fase II-III activo