Calcifications of the Thoracic Aorta on Extended Non-Contrast-Enhanced Cardiac CT Craiem, Damian; Gilles Chironi; Casciaro, Mariano Ezequiel; Graf Caride, Diego Sebastián; Simon, Alain BACKGROUND: The presence of calcified atherosclerosis in different vascular beds has been associated with a higher risk of mortality. Thoracic aorta calcium (TAC) can be assessed from computed tomography (CT) scans, originally aimed at coronary artery calcium (CAC) assessment. CAC screening improves cardiovascular risk prediction, beyond standard risk assessment, whereas TAC performance remains controversial. However, the curvilinear portion of the thoracic aorta (TA), that includes the aortic arch, is systematically excluded from TAC analysis. We investigated the prevalence and spatial distribution of TAC all along the TA, to see how those segments that remain invisible in standard TA evaluation were affected. METHODS AND RESULTS: A total of 970 patients (77% men) underwent extended non-contrast cardiac CT scans including the aortic arch. An automated algorithm was designed to extract the vessel centerline and to estimate the vessel diameter in perpendicular planes. Then, calcifications were quantified using the Agatston score and associated with the corresponding thoracic aorta segment. The aortic arch and the proximal descending aorta, "invisible" in routine CAC screening, appeared as two vulnerable sites concentrating 60% of almost 11000 calcifications. The aortic arch was the most affected segment per cm length. Using the extended measurement method, TAC prevalence doubled from 31% to 64%, meaning that 52% of patients would escape detection with a standard scan. In a stratified analysis for CAC and/or TAC assessment, 111 subjects (46% women) were exclusively identified with the enlarged scan. CONCLUSIONS: Calcium screening in the TA revealed that the aortic arch and the proximal descending aorta, hidden in standard TA evaluations, concentrated most of the calcifications. Middle-aged women were more prone to have calcifications in those hidden portions and became candidates for reclassification.

El anticomunismo de la Juventud Conservadora chilena: El caso de la Falange Nacional (1935-1957); O anticomunismo da Juventude Conservadora Chilena: O caso da Falange Nacional (1935-1957); The anticommunism of the Chilean Juventude Conservadora: the case of the Falange Nacional (1935-1957) Gomes, Gabriela Daiana El trayecto de la Juventud Conservadora a la Falange Nacional expresó una ruptura radical con el proyecto político de uno de los partidos de la derecha tradicional, el Partido Conservador (1851). Inspirado en la doctrina del humanismo cristiano, el proyecto falangista se sintetizó en el Partido Demócrata Cristiano (1957). En este artículo se analizan cuáles han sido las percepciones de los falangistas sobre el comunismo, así como la importancia adjudicada al Partido Comunista como actor legitimo del sistema de partidos.; A trajetória da Juventude Conservadora para a Falange Nacional expressou uma ruptura radical com o projeto político de um dos partidos da direita tradicional, o Partido Conservador (1851). Inspirado na doutrina do humanismo cristão, o projeto falangista se sintetizou no Partido Democrata Cristão (1957). Neste artigo se analisam quais foram as percepções dos falangistas sobre o comunismo e a importância atribuída ao Partido Comunista como um ator legítimo do sistema partidário.; The trajectory of the Juventude Conservadora (Conservative Youth) in the Falange Nacional (National Phalanx) showed a radical break with the political project of one of the parties of the traditional right, the Partido Conservador (Conservative Party, 1851). Inspired by the doctrine of Christian humanism, the Phalangist project became the Partido Democrata Cristão (Christian Democratic Party, 1957). In this article, the Phalangists’ perceptions of communism and the importance given to the Partido Comunista (Communist Party) as a legitimate actor in the party system are analyzed.

Emotion recognition and cognitive empathy deficits in adolescent offenders revealed by context-sensitive tasks González Gadea, María Luz; Herrera Murcia, Eduar; Parra, Mario; Gomez Mendez, Pedro; Báez Buitrago, Sandra Jimena; Manes, Facundo Francisco; Ibáñez Barassi, Agustín Mariano Emotion recognition and empathy abilities require the integration of contextual information in real-life scenarios. Previous reports have explored these domains in adolescent offenders (AOs) but have not used tasks that replicate everyday situations. In this study we included ecological measures with different levels of contextual dependence to evaluate emotion recognition and empathy in AOs relative to non-offenders, controlling for the effect of demographic variables. We also explored the influence of fluid intelligence (FI) and executive functions (EFs) in the prediction of relevant deficits in these domains. Our results showed that AOs exhibit deficits in context-sensitive measures of emotion recognition and cognitive empathy. Difficulties in these tasks were neither explained by demographic variables nor predicted by FI or EFs. However, performance on measures that included simpler stimuli or could be solved by explicit knowledge was either only partially affected by demographic variables or preserved in AOs. These findings indicate that AOs show contextual social-cognition impairments which are relatively independent of basic cognitive functioning and demographic variables.

Controlling Nanodomain Morphology of Epoxy Thermosets Modified with Reactive Amine-Containing Epoxidized Poly(styrene-b-isoprene-b-styrene) Block Copolymer Garate, Hernán; Goyanes, Silvia Nair; D'accorso, Norma Beatriz Controlling nanodomain morphology of nanostructured epoxy thermosets is critical to modulate the mechanical properties of the cross-linked matrix. In this contribution, we demonstrate that this can be achieved by using a suitable block copolymer containing an epoxy soluble block with the ability to react toward the epoxy system during curing. For this purpose we designed an epoxidized poly(styrene-b-isoprene-b-styrene) block copolymer incorporating amine-reactive functionalities (eSIS-AEP) in the epoxidized block as modifier for an epoxy system, which allowed the formation of nanostructured thermosets with controlled spherelike nanodomain morphology. The eSIS-AEP was obtained in two steps from poly(styrene-b-isoprene-b-styrene) (SIS) block copolymer by controlled epoxidation of the olefinic block followed by partial oxirane ring-opening reaction using 1-(2-aminoethyl)piperazine as nucleophile. Before the curing reaction it was observed that poly(styrene) blocks self-assembled to form ordered spherelike nanostructures in blends of eSIS-AEP with epoxy precursors. Since the amine-reactive moiety was incorporated to the block copolymer so that it could react toward diglicidyl ether of bisphenol A (DGEBA) at a similar temperature than the DGEBA/hardener reaction, the epoxy miscible block of eSIS-AEP (ePI-AEP) was able to react with DGEBA during curing. Once the cross-linked network was formed, the initially obtained spherelike nanodomains were preserved, indicating that no reaction-induced microphase separation of ePI-AEP subchains occurred. A completely different scenario was ascertained for epoxidized SIS block copolymer, which conducted to nonspherical nanodomains due to the uncontrolled epoxidized poly(isoprene) demixing process during the curing reaction. These results demonstrate the importance of the epoxy soluble block being reactive toward the epoxy precursors to control the morphology of the obtained nanostructure.

Duality and bosonization in Schwinger–Keldysh formulation Gamboa Saravi, Ricardo Enrique; Naon, Carlos Maria; Schaposnik, Fidel Arturo We present a path-integral bosonization approach for systems out of equilibrium based on a duality transformation of the original Dirac fermion theory combined with the Schwinger–Keldysh time closed contour technique, to handle the non-equilibrium situation. The duality approach to bosonization that we present is valid for D ≥ 2 space–time dimensions leading for D = 2 to exact results. In this last case we present the bosonization rules for fermion currents, calculate current–current correlation functions and establish the connection between the fermionic and bosonic distribution functions in a generic, non-equilibrium situation.

Síntesis y propiedades de compuestos heterocíclicos de potencial importancia tecnológica Jiménez Macías, Julyleth Paola; Caram, José Alberto; Mirifico, Maria Virginia El proyecto considera la investigación de nuevos materiales orgánicos (moléculas pequeñas) con propiedades convenientes para la transferencia de electrones y con potencial aplicación en dispositivos electrónicos y electro-ópticos. Se pretende sintetizar compuestos estables al ambiente, que presenten perfiles de absorbancias elevadas en un intervalo amplio de longitudes de onda, con posibilidad de emitir luz en la zona visible del espectro electromagnético, que sean reversiblemente reducidos/oxidados en zonas de potenciales fácilmente accesibles, que generen iones-radicales estables frente al H2O y al O2, y que en estado sólido presenten un empaquetamiento adecuado para la movilidad de la carga o para que favorezca la emisión de luz. Los derivados de 2H-imidazol-2-tiona (IM, Fig. 1) desempeñan un rol importante en síntesis orgánica, se usan como drogas terapéuticas [1], como herbicidas y fungicidas [3], y presentan capacidad inhibidora de la corrosión de metales [2]. Este trabajo se ha iniciado recientemente, y se han dado los primeros pasos hacia la síntesis de los nuevos compuestos (IM 1-3, Fig. 1). Los experimentos de síntesis se realizaron por condensación del compuesto 1,2-dicarbonílico (CD) correspondiente con tiourea (TU) (Fig. 1). La reacción se llevó a cabo en solución y en ausencia de solvente, empleando como catalizadores un ácido mineral fuerte o heteropoliácidos (HPAs). El intervalo de temperaturas investigado fue 25-150 ºC. Además, en el mismo intervalo de temperaturas se estudió la degradación térmica de tiourea. Las reacciones se siguieron por CCF, FT-IR, y CG-M. Para las reacciones en solución catalizadas por ácido mineral fuerte se siguieron los lineamientos de Wright [4]. El ensayo se llevó a cabo en pequeña escala, se empleó una relación molar R1 = TU/CD1 de 3/1 en solución de EtOH/H+ (pH=2). Después de 9 h de calentamiento a reflujo suave, y una vez alcanzada la t.a. se observó la formación de un sólido. El sólido separado por filtración, lavado (EtOH frío), y secado, está formado por un único compuesto (CCF), aún no identificado (IM-1?). Las reacciones entre CD1 y TU sin solvente se realizaron en ausencia y en presencia del HPA (H3PMo12O40 y H4PMo11VO40) [5], en las siguientes condiciones experimentales: temperatura de reacción (25, 70, 100 y 150 °C), temperatura/tiempo del pretratamiento térmico del HPA (150 y 300 °C, 24h) y relaciones molares R1=TU/CD1 (1,5-10) y R2=HPA/CD1 (0,0-0,2). En ausencia HPA, la condensación CD1 con TU no ocurrió en el intervalo 25–100 °C. Para 150°C se observaron (CCF) productos de reacción, pero se atribuyen a la degradación térmica la TU. En presencia de HPAs, ocurrió reacción química para todas las temperaturas investigadas. Las reacciones fueron siempre incompletas y resultaron en una compleja mezcla de productos. Se proyecta ensayar catálisis básica en solución y en “solvent free reactions”.

Tensiones de crecimiento y propiedades físicas de la madera de Eucalyptus dunnii implantado en Argentina; Growth stresses and physical properties of Eucalyptus dunnii wood in Argentina Hernandez, Mariano; Zaderenko, Constantino; Monteoliva, Silvia Estela El objetivo del trabajo fue evaluar tensiones de crecimiento en Eucalyptus dunnii y determinar el efecto de las propiedades físicas de la madera sobre esta variable. Se muestrearon 45 árboles de un ensayo de 19 años situado en la provincia de Corrientes, Argentina. Se realizaron determinaciones de tensiones de crecimiento a través de dos métodos: indicador de tensiones de crecimiento (GSI, CIRAD-Forêt) e índice de rajado en rollizo (IR). Se midieron las propiedades físicas, densidad básica y contracción volumétrica total y se determinó la variación radial de la densidad básica. Los resultados de GSI e IR mostraron valores más bajos que los citados para la especie (GSI: 0,0763±0,0251 mm e IR: 0,43± 0,31 %) y tuvieron buena asociación entre sí (r: 0,71). Se encontró una asociación baja entre tensiones de crecimiento con las propiedades físicas de la madera, densidad básica (r: 0,35 - 0,39) y contracción volumétrica total (r: 0,29 - 0,35). Los niveles de asociación aumentaron cuando las correlaciones se hicieron entre las estimaciones de tensiones de crecimiento y la tasa de cambio radial de la densidad básica (r: 0,59 - 0,52).; To evaluate growth stresses in Eucalyptus dunnii and determine the effect of physical wood properties on that variable, a total of 45 trees were sampled from a 19-years-old trial located at Corrientes, Argentina. Growth stresses were determined using the growth stress indicator (GSI, CIRAD-Forêt) and the log end split index (IR). The physical wood properties basic density and total volumetric shrinkage were measured and the pith-to- bark gradient of the basic density was determined. GSI and IR values obtained were lower than those cited for the species (GSI: 0,0763 ± 0,0251 mm and IR: 0,43 ± 0,31 %) and showed good association between themselves (r: 0,71). A low association between growth stresses and the physical wood properties basic density (r: 0,35 – 0,39) and volumetric shrinkage total (r: 0,29-0,35) was founded. The association levels were higher when growth stresses (GSI and IR) and the pith-to-bark gradient of the basic density (r: 0,59-0,52) were correlated.

Experimental verification of reciprocity relations in quantum thermoelectric transport Matthews, J.; Battista, Francesca; Sanchez, D.; Samuelsson, P.; Linke, H. Fundamental symmetries in thermoelectric quantum transport, beyond Onsagers relations, were predicted two decades ago but have to date not been observed in experiments. Recent works have predicted the symmetries to be sensitive to energy-dependent, inelastic scattering, raising the question whether they exist in practice. Here, we answer this question affirmatively by experimentally verifying the thermoelectric reciprocity relations in a four-terminal mesoscopic device where each terminal can be electrically and thermally biased individually. The linear-response thermoelectric coefficients are found to be symmetric under simultaneous reversal of magnetic field and exchange of injection and emission contacts. We also demonstrate a controllable breakdown of the reciprocity relations by increasing thermal bias, putting in prospect enhanced thermoelectric performance.

Effects of field-realistic doses of glyphosate on honeybee appetitive behaviour Herbert, Lucila Thomsett; Vázquez, Diego Eduardo; Arenas, Andres; Farina, Walter Marcelo Glyphosate (GLY) is a broad-spectrum herbicide used for weed control. The sub-lethal impact of GLY on non-target organisms such as insect pollinators has not yet been evaluated. Apis mellifera is the main pollinator in agricultural environments and is a well-known model for behavioural research. Honeybees are also accurate biosensors of environmental pollutants and their appetitive behavioural response is a suitable tool with which to test sub-lethal effects of agrochemicals. We studied the effects of field-realistic doses of GLY on honeybees exposed chronically or acutely to the herbicide. We focused on sucrose sensitivity, elemental and non-elemental associative olfactory conditioning of the proboscis extension response (PER), and foraging-related behaviour. We found a reduced sensitivity to sucrose and learning performance for the groups chronically exposed to GLY concentrations within the range of recommended doses. When olfactory PER conditioning was performed with sucrose reward with the same GLY concentrations (acute exposure), elemental learning and short-term memory retention decreased significantly compared with controls. Non-elemental associative learning was also impaired by an acute exposure to GLY traces. Altogether, these results imply that GLY at concentrations found in agro-ecosystems as a result of standard spraying can reduce sensitivity to nectar reward and impair associative learning in honeybees. However, no effect on foraging-related behaviour was found. Therefore, we speculate that successful forager bees could become a source of constant inflow of nectar with GLY traces that could then be distributed among nestmates, stored in the hive and have long-term negative consequences on colony performance.

Hybrid Formulations of Liposomes and Bioadhesive Polymers Improve the Hypotensive Effect of the Melatonin Analogue 5-MCA-NAT in Rabbit Eyes Quinteros, Daniela Alejandra; Vicario de la Torre, Marta; Andrés Guerrero, Vanessa; Palma, Santiago Daniel; Allemandi, Daniel Alberto; Herrero Vanrell, Rocío; Molina Martinez, Irene T. For the treatment of chronic ocular diseases such as glaucoma, continuous instillations of eye drops are needed. However, frequent administrations of hypotensive topical formulations can produce adverse ocular surface effects due to the active substance or other components of the formulation, such as preservatives or other excipients. Thus the development of unpreserved formulations that are well tolerated after frequent instillations is an important challenge to improve ophthalmic chronic topical therapies. Furthermore, several components can improve the properties of the formulation in terms of efficacy. In order to achieve the mentioned objectives, we have developed formulations of liposomes (150–200 nm) containing components similar to those in the tear film and loaded with the hypotensive melatonin analog 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT, 100 µM). These formulations were combined with mucoadhesive (sodium hyaluronate or carboxymethylcellulose) or amphiphilic block thermosensitive (poloxamer) polymers to prolong the hypotensive efficacy of the drug. In rabbit eyes, the decrease of intraocular pressure with 5-MCA-NAT-loaded liposomes that were dispersed with 0.2% sodium hyaluronate, 39.1±2.2%, was remarkably higher compared to other liposomes formulated without or with other bioadhesive polymers, and the effect lasted more than 8 hours. According to the results obtained in the present work, these technological strategies could provide an improved modality for delivering therapeutic agents in patients with glaucoma.

Effect of Cation Demixing on the Electrochemical Performance of LSCFO Cathodes for SOFCs Baque, Laura Cecilia; Soldati, Analía Leticia; Troiani, Horacio Esteban; Serquis, Adriana Cristina The commercialization of Solid oxide fuel cells (SOFCs) is still hindered by their cost and long term degradation. One of the most common degradation mechanisms of La1-xSrxFe1-yCoyO3-d (LSCFO) cathodes reported in literature is element demixing. In this work, the degradation of LSCFO cathodes deposited on Ce1-xGdxO2-d electrolytes at 800°C in air for 50 h was investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). EIS spectra from LSCFO cathodes present two contributions: one at high frequency and another at low frequency. The high frequency contribution remains invariable during the ageing treatment while the low frequency contribution continuously increases. The formation of small segregates was observed after the ageing treatment. Energy dispersive spectroscopy analysis reveals that these segregates were particularly poor in Sr.

Peri-implantational in vivo and in vitro embryo-trophoblast development after perigestational alcohol exposure in the CD-1 mouse Pérez Tito, Leticia Gabriela; Bevilacqua, Estela; Cebral, Elisa Long-term pregestational ethanol exposure induced altered fertilization and preimplantation embryogenesis. We evaluated preimplantational embryo-trophoblast differentiation, growth and invasiveness after perigestational ethanol 10% ingestion for 15 days preceding and up to day 4 (treated females [TF]: TF-D4 group) or 5 (TF-D5) of CD-1 gestation (control females [CF] with water). In TF-D4, expanded and hatched blastocyst numbers were significantly reduced (p < 0.05) versus CF-D4. Abnormal embryos and percentage of pyknotic nuclei were increased, and early blastocyst growth (nuclear number/embryo) and mitotic index was reduced (p < 0.05) versus CF-D4. On day 5 of gestation, TF-D5 presented significantly reduced total embryos and advanced embryo type 3 number versus CF-D5 (p < 0.05). During in vitro development, up to 72-hour culture, TF-D5 had reduced embryo type 1 (the least developed) and 3 percentages (p < 0.05) versus controls, whereas embryo type 2 percentage increased (p < 0.05) versus CF-D5. Embryo-trophoblast growth was studied during culture by morphometry. Embryo size ranges were classified as small, medium and large embryos. At 48-hour culture, small and medium embryos of TF had significantly increased mean area versus CF (p < 0.05), whereas large embryos had reduced mean area at 24-hour culture. Perigestational alcohol exposure up to days 4–5 induced embryo differentiation retardation, abnormal blastocyst growth and alterations of embryo-trophoblast growth and expansion during implantation, suggesting impaired regulation of trophoblast invasion and a relation with early pregnancy loss after mouse perigestational alcohol consumption.

Determinación del Factor K de ventanas: Utilización de programas de simulación de precisión para evaluar el impacto del diseño de marcos y de las condiciones climáticas Macé de Gastines, Maureen Florence Laure; Villalba, Ayelén María; Pattini, Andrea Elvira El Factor K caracteriza el comportamiento térmico de las aberturas. Varía en función del diseño, la tecnología y el material de los perfiles (marcos y hojas) y de las condiciones de entorno de la ventana. Se evalúa la sensibilidad a estas variables de los programas de simulación de precisión THERM y WINDOW, considerando dos tipos de marco de aluminio y dos conjuntos de condiciones climáticas. La carpintería con ruptura de puente térmico obtiene mejores valores de K que la tradicional, en los dos casos de condiciones de entorno. Asimismo, el porcentaje de variación debido a las distintas condiciones de entorno es similar para las dos ventanas. Estos resultados demuestran la adecuada sensibilidad de las herramientas de simulación tanto a los materiales y diseño de perfiles de las aberturas como a los parámetros climáticos, abriendo el camino hacia su uso para la certificación energética de ventanas al nivel nacional y el diseño bioclimático de edificios.

Molecular gas associated with IRAS 10361-5830 Vazzano, María Mercedes; Cappa, Cristina Elisabeth; Vasquez, Javier; Rubio, Mónica; Romero, Gisela Andrea Aims. We analyze the distribution of the molecular gas and dust in the molecular clump linked to IRAS 10361-5830, located in the environs of the bubble-shaped Hii region Gum 31 in the Carina region, with the aim of determining the main parameters of the associated material and of investigating the evolutionary state of the young stellar objects identified there. Methods. Using the APEX telescope, we mapped the molecular emission in the J = 3−2 transition of three CO isotopologues, 12CO, 13CO and C18O, over a 1. 5 × 1. 5 region around the IRAS position. We also observed the high-density tracers CS and HCO+ toward the source. The cold- dust distribution was analyzed using submillimeter continuum data at 870 μm obtained with the APEX telescope. Complementary IR and radio data at different wavelengths were used to complete the study of the interstellar medium. Results. The molecular gas distribution reveals a cavity and a shell-like structure of ∼0.32 pc in radius centered at the position of the IRAS source, with some young stellar objects projected onto the cavity. The total molecular mass in the shell and the mean H2volume density are ∼40 M and ∼(1−2)×103 cm−3. The cold-dust counterpart of the molecular shell has been detected in the far-IR at 870 μm and in Herschel data at 350 μm. Weak extended emission at 24 μm from warm dust is projected onto the cavity, as well as weak radio continuum emission. Conclusions. A comparison of the distribution of cold and warm dust, and molecular and ionized gas allows us to conclude that a compact Hii region has developed in the molecular clump, indicating that this is an area of recent massive star formation. Probable exciting sources capable of creating the compact Hii region are investigated. The 2MASS source 10380461-5846233 (MSX G286.3773-00.2563) seems to be responsible for the formation of the Hii region.

The use of artificial neural network modeling to represent the process of concentration by molecular distillation of omega-3 from squid oil; Uso de modelos de redes neuronales artificiales para representar el proceso de concentración por destilación molecular de omega-3 proveniente de aceite de calamar Rossi, Pablo Cesar; Gayol, Maria Fernanda; Renaudo, Carlos Alberto; Pramparo, Maria del Carmen; Nepote, Valeria; Grosso, Nelson The concentration of omega-3 compounds obtained for the esterification of squid oil by molecular distillation was carried out in two stages. This operation can process these thermolabile and high molecular weight components at very low temperatures. Given the mathematical complexity of the theoretical model, artificial neural networks (ANN) have provided an alternative to a classical computing analysis. The objective of this study was to create a predictive model using artificial neural network techniques to represent the concentration process of omega-3 compounds obtained from squid oil using molecular distillation. Another objective of this study was to analyze the performance of two different alternatives of ANN modeling; one of them is a model that represents all variables in the process and the other is a global model that simulates only the input and output variables of the process. The alternative of the ANN global model showed the best fit to the experimental data; La concentración de compuestos omega-3, obtenidos de la esterificación de aceite de calamar, por destilación molecular fue llevada a cabo en dos etapas. Esta operación permite procesar componentes termolábiles y de alto peso molecular a muy bajas temperaturas. Dada la alta complejidad de los modelos teóricos, las redes neuronales artificiales (RNA) conforman una alternativa al análisis computacional clásico. El objetivo de este estudio fue crear un modelo predictivo usando modelos de redes neuronales artificiales para representar el proceso de concentración de compuestos omega-3 obtenidos del aceite de calamar por destilación molecular. Otro objetivo de este estudio fue analizar el desenvolvimiento de dos alternativas de modelos RNA; uno de ellos es un modelo que representa todas las variables en el proceso y otro es un modelo global que simula solo las variables de entrada y de salida del proceso. La alternativa de un modelo RNA global mostró el mejor ajuste de los datos experimentales.

Reproductive success of the specialist brood parasite Screaming Cowbird in an alternative host, the Chopi Blackbird; Éxito reproductivo del parasito de cría especialista Molothrus rufoaxillaris en un hospedador alternativo, Gnorimopsar chopi Di Giacomo, Alejandro G.; Reboreda, Juan Carlos The Screaming Cowbird (Molothrus rufoaxillaris) is the most specialized brood-parasitic cowbird, relying almost entirely on the Bay-winged Cowbird (Agelaioides badius) as host. Recently, Screaming Cowbirds have expanded their range to areas where Bay-winged Cowbirds are absent, and they are exploiting the Chopi Blackbird (Gnorimopsar chopi). Interactions between Screaming Cowbirds and Chopi Blackbirds are largely unexplored, as is the reproductive success of the parasite in this host. Screaming Cowbirds, Chopi Blackbirds, and Bay-winged Cowbirds coexist in northeastern Argentina, providing an ideal system to explore interactions between a specialist brood parasite and an alternative host and to compare the reproductive success of the parasite in its main host and in an alternative host. Screaming Cowbirds parasitized both hosts throughout their breeding seasons (Chopi Blackbirds, mid-October to mid-January; Bay-winged Cowbirds, mid-November to mid-March). Frequency of parasitism was lower in Chopi Blackbirds than in Bay-winged Cowbirds (46% vs. 74%). Nest survival was higher in Chopi Blackbirds than in Bay-winged Cowbirds (37% vs. 15%). In successful nests, survival of Screaming Cowbird eggs and chicks was high and relatively similar in both hosts (Chopi Blackbirds: eggs, 99%; chicks, 90%; Bay-winged Cowbirds: eggs, 93%; chicks, 93%), but hatchability was lower in Chopi Blackbirds than in Bay-winged Cowbirds (52% vs. 92%). Considering (1) nest survival and (2) egg survival, hatchability, and chick survival in successful nests, the reproductive success of Screaming Cowbirds (i.e. proportion of eggs that resulted in fledglings) was 0.17 in Chopi Blackbirds and 0.12 in Bay-winged Cowbirds. Our results indicate that the Chopi Blackbird is a frequent host of the Screaming Cowbird, and parasitism of this alternative host may help explain the range expansion of this parasite in areas of Brazil where the Bay-winged Cowbird is absent.; Molothrus rufoaxillaris es el tordo parásito de cría con mayor grado de especialización y depende casi exclusivamente de Agelaioides badius como hospedador. Recientemente M. rufoaxillaris ha expandido su rango hacia áreas en las que A. badius está ausente y la evidencia indica que estarían utilizando a Gnorimopsar chopi como hospedador. Las interacciones entre M. rufoaxillaris y G. chopi son mayormente desconocidas así como el éxito reproductivo del parásito en este hospedador. Las tres especies (M. rufoaxillaris, G. chopi y A. badius) coexisten en el NE de Argentina, ofreciendo un sistema ideal para explorar las interacciones entre un parásito de cría especialista y un hospedador alternativo y para comparar el éxito reproductivo del parásito en sus hospedadores principal y alternativo. M. rufoaxillaris parasitó a ambos hospedadores a lo largo de sus temporadas reproductivas (G. chopi: mediados de octubre-mediados de enero; A. badius: mediados de noviembre-mediados de marzo). La frecuencia de parasitismo fue menor en G. chopi que en A. badius (46% vs. 74%). La supervivencia de nidos fue mayor en G. chopi que en A. badius (37% vs. 15%). En nidos exitosos, la supervivencia de huevos y pichones fue alta y relativamente similar en ambos hospedadores (G. chopi: 99% y 90%; A. badius: 93% y 93%), pero el éxito de eclosión fue menor en G. chopi que en A. badius (52% vs. 92%). Considerando: 1) la supervivencia de nidos, y 2) la supervivencia de huevos, el éxito de eclosión y la supervivencia de pichones en nidos exitosos, el éxito reproductivo de M. rufoaxillaris (i.e. proporción de huevos que resultaron en volantones) fue 0.17 en G. chopi y 0.12 en A. badius. Nuestros resultados muestran que G. chopi es un hospedador frecuente de M. rufoaxillaris y que el parasitismo de este hospedador alternativo podría ayuda a explicar la expansión del rango de este parásito en áreas de Brasil donde A. badius está ausente.

Hidroquímica e isotopía de las agua superficiales, cuerpos lagunares y suelos salinizados de la Cuenca Costera del Grupo Sur, vertiente atlántica Perez, Beatriz Alicia; Rios, Stella Maris; Dapeña, Cristina; Nillni, Adriana Mónica; Rubilar, Jorge; Locci, Fernando Se relevaron cursos de agua, cuerpos lagunares y suelos salinizados de la ciudad de Comodoro Rivadavia y zona de Rada Tilly, Argentina, ambas localidades comprendidas en la zona de estudio: Cuenca Costera del Grupo Sur de la Vertiente Atlántica. La utilización de técnicas químicas e isotópicas permitió elucidar el posible origen del elevado contenido salino de aguas y suelos. Se tomaron muestras de canalizadores superficiales (M1 a M12) de freatímetros (F1 a 4) y muestras de suelos de las adyacencias a estas. Los análisis de difracción de rayos X (DRX) y microscopía de barrido electrónico (MBE) en los suelos, determinaron la presencia predominante de sales de sodio (thenardita mayoritariamente y también halita). Las aguas se agruparon en dos tipos bicarbonatadas sódicas (M3, M5, M6, M12 y F3) y cloruradas sulfatadas sódicas (M1, M2, M7, M8, F1,F2,F4). En el 100% de las muestras, el catión dominante es el sodio y en el 67% de las muestras el anión dominante es el sulfato. La composición isotópica  (2H y 18O) de las muestras M3, M5, M6 y F3 presenta semejanzas a las del agua del acueducto M1, M2, M10 y M11, son empobrecidas y podrían ser mezcla de agua de lluvia/nieve, con agua aportada por el acuitardo más profundo, o podrían corresponder al flujo local o mezclas con agua de purga. M4 es la más enriquecida de la zona de Comodoro Rivadavia, estaría relacionada con el flujo regional y las lagunas saladas asociadas, presentando ciertas semejanzas en cuanto a isotopía, con el sistema lagunar de Rada Tilly (M7 y M8). El análisis de componentes principales (PCA) permitió determinar que características de las medidas (parámetros isotópicos y los fisicoquímicos) discriminan mejor a las muestras. Se plantea la conveniencia de analizar la composición isotópica del estroncio en las aguas contenidas en la base sedimentaria marina del sector debido a su utilidad como trazador sensible para el movimiento de aguas subterráneas y el origen de la salinidad y mediciones de radón (222Rn) para identificar la descarga de agua subterránea en agua superficial.

Tracking Solar Active Region Outflow Plasma from Its Source to the Near-Earth Environment Culhane, J. l.; Brooks, D. H.; Van Driel Gesztelyi, L.; Démoulin, P.; Baker, D.; DeRosa, M.l.; Mandrini, Cristina Hemilse; Zhao, L.; Zurbuchen, T. H. Seeking to establish whether active region upflow material contributes to the slow solar wind, we examine in detail the plasma upflows from Active Region (AR)10978, which crossed the Sun's disc in the interval 8 to 16 December, 2007 during Carrington rotation (CR)2064. In previous work, using data from the Hinode/EUV Imaging Spectrometer, upflow velocity evolution was extensively studied as the region crossed the disc while a linear force-free magnetic extrapolation was used to confirm aspects of the velocity evolution and to establish the presence of quasi-separatrix layers at the upflow source areas. The plasma properties, temperature, density and first ionisation potential bias (FIP-bias) were measured with the spectrometer during the disc passage of the active region. Global potential field source surface (PFSS) models showed that AR 10978 was completely covered by the closed field of a helmet streamer that is part of the streamer belt. Thus it is not clear how any of the upflowing AR-associated plasma could reach the source surface at 2.5 R(Sun)and contribute to the slow solar wind. However a detailed examination of solar-wind in-situ data obtained by the Advanced Composition Explorer (ACE) spacecraft at the L1 point shows that the increase in O^7+/O^6+, C^6+/C^5+ and Fe/O - a FIP-bias proxy - are present before the heliospheric current sheet crossing. These increases, along with an accompanying reduction in proton velocity and an increase in density are characteristic of both AR and slow-wind plasma. Finally we describe a two-step reconnection process by which some of the upflowing plasma from the AR could reach the heliosphere.

Distinctive PSA-NCAM and NCAM hallmarks in glutamate-induced dendritic atrophy and synaptic disassembly Podestá, María Fernabda; Yam, Patricia; Codagnone, Martín Gabriel; Uccelli, Nonthué Alejandra; Colman, David; Reines, Analia Gabriela Dendritic and synapse remodeling are forms of structural plasticity that play a critical role in normal hippocampal function. Neural cell adhesion molecule (NCAM) and its polysialylated form (PSA-NCAM) participate in neurite outgrowth and synapse formation and plasticity. However, it remains unclear whether they contribute to dendritic retraction and synaptic disassembly. Cultured hippocampal neurons exposed to glutamate (5 µM) showed a reduced MAP-2 (+) area in the absence of neuronal death 24 h after the insult. Concomitantly, synapse loss, revealed by decreased synaptophysin and post-synaptic density-95 cluster number and area, together with changes in NCAM and PSA-NCAM levels were found. Dendritic atrophy and PSA-NCAM reduction proved NMDA-receptor dependent. Live-imaging experiments evidenced dendritic atrophy 4 h after the insult; this effect was preceded by smaller NCAM clusters (1 h) and decreased surface and total PSA-NCAM levels (3 h). Simultaneously, total NCAM cluster number and area remained unchanged. The subsequent synapse disassembly (6 h) was accompanied by reductions in total NCAM cluster number and area. A PSA mimetic peptide prevented both the dendritic atrophy and the subsequent synaptic changes (6 h) but had no effect on the earliest synaptic remodeling (3 h). Thus, NCAM-synaptic reorganization and PSA-NCAM level decrease precede glutamate-induced dendritic atrophy, whereas the NCAM level reduction is a delayed event related to synapse loss. Consequently, distinctive stages in PSA-NCAM/NCAM balance seem to accompany glutamate-induced dendritic atrophy and synapse loss.

Characterization of the turbulent magnetic integral length in the solar wind: from 0.3 to 5 astronomical units Ruiz, Maria Emilia; Dasso, Sergio Ricardo; Matthaeus, W. H.; Weygand, J. M. The solar wind is a structured and complex system, in which the fields vary strongly over a wide range of spatial and temporal scales. As an example, the turbulent activity in the wind affects the evolution in the heliosphere of the integral turbulent scale or correlation length [λ], usually associated with the breakpoint in the turbulent-energy spectrum that separates the inertial range from the injection range. This large variability of the fields demands a statistical description of the solar wind. We study the probability distribution function (PDF) of the magnetic-autocorrelation lengths observed in the solar wind at different distances from the Sun. We used observations from the Helios, ACE, and Ulysses spacecraft. We distinguished between the usual solar wind and one of its transient components (interplanetary coronal mass ejections, ICMEs), and also studied solar-wind samples with low and high proton beta [βp]. We find that in the last three regimes the PDF of λ is a log-normal function, consistent with the multiplicative and nonlinear processes that take place in the solar wind, the initial λ (before the Alfvénic point) being larger in ICMEs.