Gas Flow in a Channel Semiobstructed by a Porous Media Dalponte, Diego David; Silin, Nicolas; Clausse, Alejandro An experimental study of a gas flow in a narrow channel partially obstructed by a regular array of wires is presented. The velocity profile along the channel was measured by means of a hot-wire anemometer, inside and outside the obstructed region. Flow instabilities were found in the free zone adjacent to the porous region, which were characterized by the standard deviation and the power spectrum of the signal of the anemometer. The experimental profiles were compared with numerical simulations using a two-dimensional Lattice Boltzmann model.

Niños y niñas en el espacio urbano: La provincia de Buenos Aires entre fines del siglo XIX y principios del XX de Paz Trueba, Yolanda Edith El crecimiento poblacional producto de la inmigración masiva y la consecuente urbanización acelerada de ciudades y pueblos por los que atravesó Argentina en las décadas finales del siglo XIX, se contaron entre los avances más destacados del momento. En este contexto, la pobreza adquirió un sentido de peligrosidad que se hizo visible en la figura de vagabundos, mendigos y especialmente para nuestro interés, de los niños que deambulaban por las calles mendigando o desempeñándose en trabajos que los mantenían largas horas fuera del hogar, cuando tenían uno. El objetivo de este trabajo es analizar, en el contexto de modernización y desarrollo de la urbanización por la que atravesaron el centro y sur de la provincia de Buenos Aires, la recepción que la sociedad local hacía de la presencia de los niños en la vía pública, y si existían algunas diferencias en relación al género. Proponemos un primer acercamiento que retome los dichos de la prensa local al respecto, para contrastarlos luego en una segunda instancia, con documentos de las Defensorías de Menores y la policía, de manera de problematizar esa percepción.

Objeción de conciencia sin precedentes Legarre, Santiago La presente nota analiza un caso de objeción de conciencia a la luz de la doctrina de la obligatoriedad atenuada del precedente desarrollada por la Corte Suprema de Justicia de la Nación. Fundamentalmente, y en línea con la investigación encarada por el suscripto, se analizan problemas prácticos de la falta de mayoría en un caso de la Corte Suprema.

Justification Logic as a foundation for certifying mobile computation Bonelli, Eduardo Augusto; Feller, Federico We explore an intuitionistic fragment of Artëmov's . Justification Logic as a type system for a programming language for . mobile units. Such units consist of both a code and a certificate component. Our language, the . Certifying Mobile Calculus, caters for code and certificate development in a unified theory. In the same way that mobile code is constructed out of code components and extant type systems track local resource usage to ensure the mobile nature of these components, our system . additionally ensures correct . certificate construction out of certificate components. We present proofs of type safety and strong normalization for a run-time system based on an abstract machine.

La abstracción en la teoría del conocimiento de Hegel Ferreiro, Hector Alberto En la filosofía de Aristóteles y en la filosofía escolástica de cuño aristotélico, la abstracción constituía un acto fundamental del proceso cognitivo: marcaba el salto o ascenso de la sensibilidad a la inteligibilidad, del conocimiento del individuo al conocimiento de su esencia. En la teoría del conocimiento de Hegel, por el contrario, el concepto abstracto o, como Hegel prefiere llamarlo, la “representación abstracta” o “representación universal” es tan sólo un momento intermedio en el proceso fluído que va del conocimiento del objeto como algo sensible -en la forma de la intuición y la subforma de la imagen- al conocimiento de su naturaleza intrínseca -en la forma del pensar. Sobre la base, por un lado, de los escasos textos en los que Hegel se ocupa expresamente del tema, y, por el otro, de la contextualización de estos textos en un análisis general de la filosofía del espíritu subjetivo teórico, el presente trabajo busca reconstruir las tesis fundamentales de Hegel sobre la abstracción y esclarecer con ello el sentido y función que la misma tiene en su teoría del conocimiento.; n both Aristotelian philosophy and the scholastic philosophy that bears its stamp, the concept of abstraction constitutes a fundamental act in the cognitive process; it signaled the leap or ascent from the realm of the senses to the realm of intellection, from knowledge of the individual to knowledge of his essence. By way of contrast, in Hegel's theory of knowledge, the abstract concept -or, as Hegel himself preferred to call it, “abstract representation” or “universal representation”- is nothing but an intermediate moment in the fluid process of going from knowing the object as something given to the senses -in the form of intuition and the subform of image- to knowing its intrinsic nature -in the form of thought. Based on the scant writings by Hegel wherein he expressly addresses the matter, and by subsequently placing these texts into the broader context of an analysis of Hegel's philosophy of theoretical subjective spirit, this paper attempts to reconstruct Hegel's most significant ideas on abstraction. Hopefully, this will serve to clarify both the meaning and the role of that notion in Hegelian theory of knowledge.

Rupturas y continuidades en los modos de hacerse joven Capriati, Alejandro Jose ¿Qué hay de novedoso en las prácticas culturales y en las experiencias nocturnas de las generaciones más jóvenes? ¿Las prácticas culturales y los espacios de sociabilidad juveniles constituyen experiencias facilitadoras de procesos reflexivos, “de ampliación de conciencia”, acerca de las propias condiciones y perspectivas de existencia? ¿En qué medida estas prácticas y espacios juveniles tienen la potencialidad de modificar la reproducción de desigualdades sociales?

Antitumor Protection by NGcGM3/VSSP Vaccine Against Transfected B16 Mouse Melanona Cells Overexpressing N-Glycolylated gangliosides Segatori, Valeria Inés; Otero, Laura; Fernandez, Luis Enrique; Gomez, Daniel Eduardo; Alonso, Daniel Fernando; Gabri, Mariano Rolando Background: Cancer vaccines are designed to modulate immunological responses against tumor cells through the presentation of tumor antigens. Materials and Methods: The mouse mRNA of the cytidine monophospho-N-acetylneuraminic acid hydroxylase (Cmah) gene, the enzyme that catalyzes the synthesis of N-glycolylneuraminic acid (NGc), was cloned and transfected into the B16 melanoma cell line. Transfected cells (B16-H) were characterized and used as an NGcGM3-positive primary tumor model for the evaluation of the therapeutic activity of the NGcGM3/VSSP vaccine. Results: The presence of NGcGM3 in B16-H cells promoted proliferation and adhesion in vitro, but resulted in reduced tumorigenicity in vivo. However, B16-H cells developed growing tumors in mice where NGcGM3/VSSP vaccination induced a therapeutic antitumor activity. NGcGM3/VSSP was ineffective in mice inoculated with parental B16 or B16-H cells that had lost NGcGM3 expression. Conclusion: The presence of NGcGM3 in tumor cells is critical for the antitumor activity of NGcGM3/VSSP vaccine.

Expression of heme oxygenase-1 in non small cell lung cancer (NSCLC) and its correlation with clinical data Degese, María Sol; Mendizábal, Javier Enrique; Gandini, Norberto Ariel; Gutkind, J. Silvio; Molinolo, Alfredo; Hewitt, Stephen M.; Curino, Alejandro Carlos; Coso, Omar Adrian; Facchinetti, Maria Marta While changes in heme oxygenase (HO-1) in lung cancer have already been reported, conflicting results were obtained for enzyme expression in human lung cancer specimens. Therefore, the aim of this work was to study HO-1 expression in a large collection of human lung cancer samples. For this purpose, we analyzed the expression of HO-1 in an organized tissue microarray (TMA) and investigated its correlation with clinicopathological data. Ninety-six percent of tumor samples were positive for HO-1, and the expression of HO-1 was significantly higher in cancerous than in non-cancerous tissues. Importantly, HO-1 expression correlated with advanced stages and lymph node involvement. Additionally, quantitative RT-PCR in 18 pairs of human lung carcinomas and their adjacent non-malignant tissues was performed. Our results demonstrate that HO-1 protein is upregulated in epithelial malignant cells in NSCLC and its expression is associated with higher stages of the disease. Additionally, different subcellular localization is observed between tumor and adjacent non-malignant tissues.

Physico-Chemical and Mechanical Properties of Apple Disks Subjected to Osmotic Dehydration and Different Drying Methods Sosa, Natalia; Salvatori, Daniela Marisol; Schebor, Carolina Claudia The effect of sucrose infusion (SI) pretreatment and dehydration methods (freeze and air drying) on physical and textural properties of apple disks were analyzed. Dried samples were humidified between 11% and 43% relative humidity (RH) at 20 °C. Control samples (air- and freeze-dried) behaved similarly regarding water sorption and glass transition temperature. SI process caused important changes in the water sorption behavior of air-dried samples. Nuclear magnetic resonance relaxation times values (T 2) for freeze-dried apples were higher than those for air-dried samples. Samples subjected to previous SI always presented lower T 2 values because they had lower water contents. The dehydration method also affected the mechanic behavior. Air-dried samples exhibited higher F max values during puncture assay than those obtained for freeze-dried samples. SI samples showed higher F max values for both drying methods. The crust formed during air drying generated crispier materials along the whole RH range, while freeze-dried matrices were more deformable with the increase in RH. SI pretreatment also allowed diminishing browning development. The results obtained are useful in the choice of processing technologies of organoleptically acceptable dehydrated fruits for direct consumption or for their incorporation into compound foods.

Application of the multi-standard methodology for calculating 1H NMR chemical shifts Sarotti, Ariel Marcelo; Pellegrinet, Silvina Carla Gauge including atomic orbitals (GIAO)1H NMR chemical shift calculations have been performed for 66 organic compounds at 72 di fferent levels of theory using the multi-standard approach (MSTD) previously developed for 13C NMR. This straightforward computational technique involves the combination of methanol and benzene as standards. The studied methodology has been shown to predict 1H NMR chemical shifts efficiently at different levels of theory.

Sunflower-Soybean Intercrop. Productivity under different water conditions and sowing managements Andrade, José Francisco; Cerrudo, Anibal Alejandro; Rizzalli, Roberto Héctor; Monzon, Juan Pablo The sunflower (Helianthus annus L.)–soybean [Glycine max (L.) Merr.] intercrop has emerged as an option that increases land productivity in the southern Pampas of Argentina, compared with sole crops, because of complementary use of resources between species. A common management practice for this intercrop consists of delay soybean sowing, although delayed planting reduces the capacity of soybean to capture resources. Simultaneous sowing could improve total intercrop productivity because of an increase in soybean grain yield with no or little detrimental effects on sunflower grain yield. The objectives of this study were to analyze the response of the sunflower–soybean intercrop and of their component species under different sowing management (i.e., relay or simultaneous sowing) and water availability conditions. Three experiments were conducted at Balcarce, Argentina. Four cropping systems were evaluated: (i) sunflower–soybean intercrop with simultaneous sowing management (I00), (ii) sunflower– soybean intercrop with 30 d of delay between sunflower and soybean sowing (I30), (iii) sunflower sole crop (SUN), and (iv) soybean sole crop (SOY). Sunflower–soybean intercrop grain yield tend to be higher than that for sole crops of the component species. This yield advantage for intercrop increased with water availability and was associated with an increase in intercropped soybean productivity. Intercrop sowing management had no effect on total intercrop grain yield. However, simultaneous sowing increased soybean contribution to intercrop yield. Finally, our results indicate that agronomic practices that promote.

Evaluation of pyrethroids toxicity in a laboratory strain and a field population of Rachiplusia nu (Lepidoptera: Noctuidae) using two bioassay techniques; Evaluación de la toxicidad de piretroides en una cepa de laboratorio y una población de campo de Rachiplusia nu (Lepidoptera: Noctuidae) usando dos métodos de bioensayo Russo, Romina; Gamundi, Juan C; Alzogaray, Raúl Adolfo Soybean is the most important crop in Argentina and Rachiplusia nu (Gueneé) (Lepidoptera: Noctuidae) is one of its main pests. In this study, the toxicity of five pyrethroids applied topically and by exposure to films on filter paper was evaluated on third instar larvae from a laboratory strain and a field population of R. nu. Four cyanopyrethroids and one noncyanopyrethroid (permethrin) were tested. All cyanopyrethroids showed the same order of increasing toxicity, regardless of the form of application and origin of the larvae: cypermethrin < lambda-cyhalothrin < deltamethrin < beta-cyfluthrin. Knock down Dose 50% and Knock down Time 50% values increased as a function of the solubility of cyanopyrethroids in water. Permethrin showed a different behavior: it was the most toxic insecticide for the laboratory strain when applied topically, but the least toxic when larvae were exposed to filter papers. In general, the pyrethroids were more toxic for laboratory larvae than for the field ones. After calculating Resistance Factor (RF) values, low-moderate resistance to permethrin, cypermethrin and lambda-cyhalothrin was observed in the experiments with topical application. However, exposure to films on filter papers failed to detect resistance. There was not correlation between the RF values obtained by both methods. These results suggest that the population of studied here has low-moderate resistance to some pyrethroids, and that topical application is a more appropriate method for quantifying resistance than exposure to insecticide films on filter paper.; La soja es el cultivo más importante en la República Argentina y Rachiplusia nu (Gueneé) (Lepidoptera: Noctuidae), una de sus principales plagas. En este estudio se evaluó la toxicidad de cuatro cianopiretroides y un no-cianopiretroide, aplicados en forma tópica o por exposición a filmes sobre papeles de filtro, en ninfas del tercer estadio de una cepa de laboratorio y una población de campo de R. nu. Todos los cianopiretroides mostraron el mismo orden de toxicidad creciente, independientemente de la forma de aplicación y del origen de las larvas: cipermetrina < ?-cihalotrina < deltametrina < ß-ciflutrina. Los valores de Dosis de Volteo para el 50% (DV50) y de Tiempo de Volteo para el 50% (TV50) aumentaron en función de la solubilidad de los cianopiretroides en agua. El no-cianopiretroide permetrina mostró un comportamiento diferente: fue el insecticida más tóxico para la cepa de laboratorio cuando se hizo una aplicación tópica, pero el menos tóxico cuando las larvas fueron expuestas a filmes sobre papeles de filtro. En general, todos los piretroides fueron más tóxicos para las larvas criadas en laboratorio que para las provenientes del campo. La estimación de los valores de Factor de Resistencia (FR) permitió establecer que la población de campo presentaba resistencia moderada o baja a permetrina, cipermetrina y ?-cihalotrina, cuando los insecticidas fueron aplicados en forma tópica. Sin embargo, no se detectó resistencia cuando se realizó la exposición en papeles de filtro tratados. No hubo correlación entre los valores de FR obtenidos por ambos métodos. Estos resultados sugieren que la población de campo de R. nu estudiada, presentaba resistencia moderada a algunos piretroides, y que la aplicación tópica es un método más apropiado que la exposición a filmes sobre papeles de filtro para cuantificar la resistencia.

Polyvinyl alcohol-pectin cryogel films for controlled release of enrofloxacin Martinez, Nelida Yanina; Piñuel, Maria Lucrecia; Castro, Guillermo Raul; Breccia, Javier Dario The release of enrofloxacin entrapped in polyvinyl alcohol (PVA) cryogel at pH 5.5 showed a first-order kinetic, releasing 69.7% of the antibiotic after 4.5 h at 37 °C. In order to slow down the fluoroquinolone release rate, high-methoxylated pectin was added into the cryogel (PVA-P). A film containing 1.0% (w/v) HM pectin and 5.0 μg/ml enrofloxacin released only 3.7% of the antibiotic after 4.5 h. Since the FTIR spectrum showed that most of the interactions between PVA-P matrix and enrofloxacin were due to polar groups (carboxylate and amine), a two-layer film system was designed to modulate the releasing rate of the drug. The top film equilibrated with 0.75 or 1.5 M NaCl release up to 41.9% and 89.0% of the enrofloxacin in 4 h, respectively. The release rate of enrofloxacin was found dependent on NaCl concentration in the upper gel layer. The two-layer cryogel system showed attractive features for transcutaneous antibiotic delivery.

Geographical and botanical classification of honeys and apicultural products by chemometric methods. A review Camiña, José Manuel; Pellerano, Roberto Gerardo; Marchevsky, Eduardo Jorge Evaluations of adulteration, geographical and botanical origin of bee-products are matters of great interest worldwide. These trends are principally related to the international market of food commodities. The chemometric tools appear as new analytical complements which, in recent years, were successfully used to define the geographical and botanical origin of food raw materials or to detect possible adulterations. The classification can be possible using different analysis criteria, such as minor and trace elements, as well as sugars and other items by the chemometric analysis. This review contains a survey of the current multivariate methods published between January 1999 and February 2011, used for the classification and authentication of honey and other bee-products. References are ordered in a way to allow easy reading and further search.

"Semillas en tierras estériles". La recepción del APRA en la Argentina de mediados de la década de los treinta. Sessa, Leandro Si bien los orígenes de la Alianza Popular Revolucionaria Americana (APRA) están relacionados con las repercusiones continentales del movimiento reformista universitario, en la década de los veinte, la presencia del aprismo en la Argentina tuvo ecos más allá de esos antecedentes. Durante la década de los treinta, militantes interesados en las ideas antiimperialistas procuraron aclimatar el aprismo a la realidad Argentina. A través del análisis de los artículos escritos en la revista Claridad por Alberto Faleroni, principal referente del “aprismo argentino”, y de la reconstrucción de la experiencia del Partido Aprista Argentino (PAA), procuramos dar cuenta de las posibilidades y dificultades en torno de los intentos de construir una propuesta inspirada en el APRA. Este análisis nos permite indagar en el recorrido de ciertas ideas vinculadas al antiimperialismo, el nacionalismo y la perspectiva continental, que circulaban en redes políticas e intelectuales cercanas al socialismo.; Even though the origins of the Popular Revolutionary American Alliance [APRA] are related to the continental impact of University Reform movement, in the 1920's the APRA's presence in Argentina had echoes beyond these precedents. During the thirties, militants interested in anti-imperialist ideas tried to adapt aprism to the argentine context. Through the analysis of Claridad magazine articles written by Alberto Faleroni, the main reference point of "Argentinean aprism", and the reconstruction of the Partido Aprista Argentino [PAA] experience, we try to explore the possibilities and difficulties of the attempts to build an APRA-inspired project. This analysis allows us to investigate the itineraries of certain ideas linked to anti-imperialism, nationalism and continental perspective, which circulated in political and intellectual networks close to socialism.

Helechos epífitos de Alsophila setosa (Cyatheaceae, Pteridophyta) en la Provincia de Misiones, Argentina; Epiphyte ferns on Alsophila setosa (Cyatheaceae, Pteridophyta) from Misiones province, Argentina Marquez, Gonzalo Javier; Yañez, Agustina Los cáudices de los helechos arborescentes presentan condiciones particulares que favorecen el establecimiento de epífitas. En este trabajo se estudiaron los helechos que crecen sobre Alsophila setosa (Cyatheaceae, Pteridophyta) en la provincia de Misiones. Se encontraron 21 especies, que se agruparon en 10 géneros y 5 familias. La familia más diversa fue Polypodiaceae, con 8 especies, y los géneros mejor representados fueron Asplenium (6) y Pecluma (4). Se presenta una clave para la identificación de los taxa involucrados. La gran cantidad de especies encontradas refleja la importancia de Alsophila setosa como reservorio de diversidad biológica en el bosque atlántico.; Trunks of tree ferns offer especially distinctive substrates to support epiphytes. In this paper, ferns that grow on Alsophila setosa Kaulf. from Misiones were studied. A total of 21 species, from 10 genera and 5 families, were recorded. Polypodiaceae (8) had greater specific diversity. Richest genera were Asplenium (6) and Pecluma (4). A key is presented to identify the taxa involved. The high epiphytic diversity found suggests that Alsophila setosa plays an important role as a biodiversity reservoir in the Atlantic forest.

Multivariable 2-sliding mode control for a wind energy system based on a double fed induction generator Evangelista, Carolina Alejandra; Valenciaga, Fernando; Puleston, Pablo Federico The purpose of this paper is to present a control strategy using Multiple Input/Multiple Output (MIMO) Second Order Sliding Modes (SOSM) for a grid-connected variable-speed Wind Energy Conversion System (WECS). The latter is based on a Double Fed Induction Generator (DFIG) in a bidirectional configuration with slip power recovery. Its points of operation can be electronically controlled and, with them, two independent control objectives can be stated. Thus, a control is designed to maximize the energy captured from the wind and to regulate the stator reactive power, contributing to the compensation of the power factor according to grid requirements. The proposed technique can be applied to nonlinear MIMO systems and allows to make a separate design for each component of the controller. For these designs the Super- Twisting algorithm is employed in this work, which possesses excellent properties regarding simplicity of implementation and online operation, and robustness against uncertainties and external disturbances. Finally, representative simulation results are presented and analyzed. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Charge regulation in redox active monolayers embedded in proton exchanger surfaces Ricci, A.M.; Tagliazucchi, Mario Eugenio; Calvo, Ernesto Julio Experimental evidence of the variation in redox potential of osmium pyridine complexes tethered to a Au surface by thiol or diazonium chemistry at different ionic concentration and electrolyte pH is described. The interplay between the charged redox and acid groups is described by a charge regulation model based on PM-IRRAS spectroscopic evidence on the different degrees of surface protonation.

Sobre la cuestión de la crítica en la obra de Arturo Andrés Roig; About the question of criticism in the work of Arturo Andrés Roig Contardi, Laura Aldana Centramos la atención en la noción de crítica del pensamiento de Arturo Andrés Roig. El problema se aborda partiendo del vínculo que se establece entre la crítica y la noción de vigilancia epistemológica de Gastón Bachelard. Consideramos a continuación la crítica como ejercicio de la sospecha. Finalmente, se analiza el aspecto social de la crítica, esto permite relacionar la producción teórica de Roig con la teoría crítica, especialmente con el pensamiento de Max Horkheimer. En este sentido, enfatizamos la indagación sobre la función social de la filosofía ya que implica una ampliación de la crítica.; We focus our attention on the concept "criticism" thinking by Arturo Andrés Roig. We tackle this question starting from the link between "criticism" and "epistemological vigilance" of Gaston Bachelard. We then consider the criticism like suspicion. Finally, we analize the social aspect of the criticism, that allow to link the theoretical production of Arturo Roig whit the critical theory, especially whit Horkheimer´s thinking. In this respect, we emphasize the inquiry about the social function of the philosophy, because that involves an enlargement of criticism.

Measurement of ivermectin concentrations in target worms and host gastrointestinal tissues: Influence of the route of administration on the activity against resistant Haemonchus contortus in lambs Lloberas, Maria Mercedes; Alvarez, Luis Ignacio; Entrocasso, Carlos; Virkel, Guillermo Leon; Lanusse, Carlos Edmundo; Lifschitz, Adrian Luis The influence of the administration route on the relationship between efficacy and ivermectin concentration profiles achieved in the bloodstream, the gastrointestinal mucosal tissues/fluid contents and within a target abomasal parasite (Haemonchus contortus) was evaluated in lambs. Twenty-six (26) parasitized lambs were assigned into three experimental groups: untreated (control) and ivermectin treated by the subcutaneous and intraruminal route at 0.2. mg/kg. Blood samples were collected between 0 and 15. days post-treatment (plasma disposition study). Four animals from each group were sacrificed at day 3 post-treatment. Mucosa and content samples from abomasum and small intestine and adult specimens of H. contortus were collected. Drug concentrations were measured by HPLC. Individual fecal egg counts were evaluated at -1, 3 and 15. days post treatment. Post-mortem examination was done at day 15 post-treatment. Adult nematodes recovered from the digestive tract were counted and identified by species. Ivermectin plasma availability was higher (P< 0.05) after the subcutaneous administration (129. ng.d/ml) compared to the intraruminal treatment (58.4. ng.d/ml). However, ivermectin concentrations measured in the gastrointestinal contents were higher in lambs treated by the intraruminal route. The mean ivermectin concentrations achieved (3. days post-treatment) in the abomasal content were 143. ng/g (intraruminal) and 2.53. ng/g (subcutaneous). Ivermectin concentrations were 15-fold higher in H. contortus recovered from intraruminally treated lambs. Whereas the subcutaneous administration reduced the number of adult nematodes from 4376 to 1300, the number of adult nematodes after the treatment with ivermectin given by the intraruminal route was 206 (P< 0.05). The higher ivermectin concentrations achieved in the digestive tract shortly after the intraruminal treatment may account for the observed enhanced efficacy compared to the parenteral administration against parasites of reduced susceptibility.