Spectroelectrochemical evidence for the nitrosyl redox siblings NO +, NO., and NO- coordinated to a strongly electron-accepting FeII porphyrin: DFT calculations suggest the presence of high-spin states after reduction of the FeII-NO - complex Pellegrino, Juan; Hübner, Ralph; Doctorovich, Fabio; Kaim, Wolfgang Experimental and computational results for the electron-deficient porphyrin complex [Fe(NO)(TFPPBr8)] (1; TFPPBr8=2,3,7,8,12,13,17, 18-octabromo-5,10,15,20-tetrakis(pentafluorophenyl)porphyrin) are reported with respect to its electron-transfer behavior. Complex 1 undergoes three one-electron processes: two reversible reductions and one irreversible oxidation. Spectroelectrochemical measurements (IR and UV/Vis/NIR spectroscopy) of 14NO- and 15NO-containing material indicate that the first reduction to 1- occurs largely on the NO ligand to produce nitroxyl anion (NO-) character, as evident from the considerable change in νNO from 1715 to around 1550 cm-1. The second reduction to 12- does not result in a further shift of νNO to lower frequencies, but to a surprising high-energy shift to 1590 cm-1. This and the notable changes of the characteristic porphyrin vibrations as well as significant changes of the UV/Vis absorptions indicate a porphyrin-centered process; DFT calculations predict the shift of νNO to higher frequencies for the intermediate- and high-spin states of 12-. The oxidation of 1 is irreversible on the voltammetry timescale, but chemically reversible in spectroelectrochemical experiments, suggesting that the cationic form dissociates to the corresponding ferric porphyrin and NO. DFT calculations support the interpretation of the experimental results. En este trabajo se estudia el comportamiento redox del complejo {FeNO}7 con sustituyentes atractores de electrones, [Fe(NO)(TFPPBr8)]=1 (TFPPBr8=2,3,7,8,12,13,17,18- octabromo-5,10,15,20-tetrakis(pentafluorofenil)porfirina) mediante experimentos de espectroelectroquímica y cálculos computacionales. El complejo 1 presenta tres procesos electroquímicos de un electrõn: dos reducciones reversibles y una oxidaciõn irreversible. El considerable cambio de νNO de 1715 cm-1 a ≈ 1550 cm-1 indica que la primera reducciõn a 1- involucra en gran medida al ligando NO. Para la segunda reducciõn a 12- se observa, sorprendentemente, un cambio de νNO a ≈ 1590 cm-1. Este pequeño corrimiento de νNO y los cambios notables de las vibraciones asociadas a modos de la porfirina, así como los cambios significativos en la banda UV/Vis de Soret, indican un proceso centrado en la porfirina; los cálculos DFT predicen el corrimiento de νNO a mayores frecuencias para los estados de spin intermedio y alto de 1 2-. En cuanto a la oxidaciõn de 1, la onda irreversible en la voltametría cíclica sugiere que la forma catiõnica 1 + se disocia dando la porfirina de hierro(III) y NO; sin embargo, en el experimento espectroelectroquímico el proceso resulta reversible, recuperándose la νNO de 1 al reducir. Los cálculos DFT apoyan la interpretaciõn de los resultados experimentales. All in a spin: IR and UV/Vis spectroelectrochemistry reveal that the oxidation and the first reduction of [Fe(NO)(TFPPBr8)] (TFPPBr8= 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(pentafluorophenyl)porphyrin) mainly affect the FeNO moiety. In the two-electron-reduced form, the added electrons appear mainly located on the porphyrin, and DFT calculations suggest an intermediate- or high-spin state (see figure).

The use of actometry and electronic nose devices to assess the locomotor activity of two species of Coccinellidae (Coleoptera) Heit, Guillermo Eugenio; Messina, Valeria Marisa; Mareggiani, Graciela Silvia; Cohen, Rosa Graciela; Carrizo, Paola The effect of odor signals on the locomotor activity of Cycloneda sanguinea and Harmonia axyridis was evaluated using two different actometric devices. The purpose of the analysis was to differentiate between the responses elicited by direct contact with the substrates and the responses that occurred if the coccinellids were exposed only to volatiles and had no direct substrate contact. The odor profile of the environmental volatiles (semiochemicals) in the bioassays was analyzed using an electronic nose (Modular Sensor System Moses II). The treatments used included volatiles emitted by pepper leaves (healthy or infested with Myzus persicae), M. persicae molts and honeydew, and healthy leaves treated with an artificial inducer of the systemic acquired response to herbivory (AISAR). The results suggest that a specific stimulus linked to aphid-host interaction would trigger a distinctive locomotor activity pattern in H. axyridis, with or without any contact with the aphids or the host plant. In contrast, C. sanguinea was not able to differentiate between volatiles from infested or uninfected pepper leaves or to distinguish these volatiles from clean filter paper (control). If C. sanguinea was in contact with aphid-infested pepper leaves (regardless of the previous prey density), it moved slowly and scanned the area exhaustively; H. axyridis showed significantly reduced locomotor activity when it was in contact with aphid-infested pepper leaves or aphid molts and honeydew, all reliable signals of the presence of a food source. In both species, treatment with Actigard (AISAR: Acibenzolar-S-methyl) failed to evoke the behavioral response observed in the treatment with aphid-infested pepper plants. The study also demonstrated that the E-nose can differentiate among blends of volatiles released from cut healthy or aphid-infested pepper leaves.

Performance of a multipurpose research electrochemical reactor Henquín, Eduardo Rubén; Bisang, Jose Maria This paper reports on a multipurpose research electrochemical reactor with an innovative design feature, which is based on a filter press arrangement with inclined segmented electrodes and under a modular assembly. Under bipolar connection, the fraction of leakage current is lower than 4%, depending on the bipolar Wagner number, and the current distribution is closely uniform. When a turbulence promoter is used, the local mass-transfer coefficient shows a variation of ±10% with respect to its mean value. The fluidodynamics of the reactor responds to the dispersion model with a Peclet number higher than 10. It is concluded that this reactor is convenient for laboratory research.

Fossil cocoons associated with a dinosaur egg from Patagonia, Argentina Genise, Jorge Fernando; Sarzetti, Laura Cristina Eight fossil (Cretaceous) insect cocoons were discovered within the infillings of a broken dinosaur egg of a clutch from a Patagonian locality. Cocoons are considered to be in situ based on detailed preservation of thin, delicate walls with surface texture, infillings that are similar to the surrounding rock matrix and the clustered distribution of cocoons in only one egg out of the clutch of five eggs. According to the shape, size, and thin wall with surface texture, the cocoons are interpreted as having been produced by wasps. The wasps may have been attracted to the egg because of the presence of scavenging insects feeding on the decaying organic matter, or they may have been attracted to spiders feeding on the scavenging insects. In either scenario, after attacking the insects or spiders inside the sand infillings of the egg, the wasp larvae produced the cocoons described herein. The presence of wasps, which are at the top of the scavenging food webs, suggests that a complex community of invertebrates would have developed around rotten dinosaur eggs.

New materials of Argentoconodon fariasorum (Mammaliaformes, Triconodontidae) from the Jurassic of Argentina and its bearing on triconodont phylogeny Gaetano, Leandro Carlos; Rougier, Guillermo W. Argentoconodon fariasorum is the only triconodont from the Jurassic of South America. Originally described on the basis of an upper molariform, A. fariasorum is now known by several specimens, including one that preserves most of its dentition, upper and lower jaws, and several postcranial elements. Close anatomical similarity exists between Argentoconodon fariasorum, Ichthyoconodon jaworowskorum, from the Cretaceous of Morocco, and the likely Jurassic Volaticotherium antiquus, from China. The results of a phylogenetic analysis including most taxa relevant to addressing triconodont phylogenetic relationships show Argentoconodon and Volaticotherium as a clade, which in turn is more closely related to Ichthyoconodon than to any other taxon. Our most parsimonious hypotheses support a triconodontid ancestry for Argentoconodon, Ichthyoconodon, and Volaticotherium as members of the monophyletic traditional subfamily Alticonodontinae. The inclusion of Argentoconodon among alticonodontines extends the geographical and temporal distribution of this triconodont subfamily to the South American Early Jurassic, resulting in extensive ghost lineages for many triconodontid groups. Postcranial similarities between Argentoconodon and Volaticotherium make it possible that the Argentinean taxon might have had gliding capabilities; if this is the case, our cladistic analysis highlights the possible existence of a gliding clade of triconodonts of wide distribution from at least as early as the Early Jurassic.

La Tasa de miseria de los ogares. Una aproximación metodológica y conceptual a la medición, distribución espacial y variaciones de la pobreza extrema en Argentina durante la década del noventa.; Misery Rate of Homes. A methodological and conceptual approximation to measuring spatial distribution and variations of extreme poverty in Argentina during the decade of the nineties Longhi, Hugo Fernando Las brisas marinas son fenómenos meteorológicos a escala local que ejercen su influencia sobre la costa durante todo el año, sin embargo son escasos los trabajos realizados en la costa argentina. El objetivo de la presente investigación es caracterizar y determinar la ocurrencia de las brisas de mar en Monte Hermoso, balneario ubicado en el suroeste de la Provincia de Buenos Aires (61º15’55’’W, 38º59’33’’S). El periodo analizado abarca desde diciembre de 2007 a julio de 2010. Se aplicó la metodología propuesta por Zubillaga y Piccolo (1977/78a) y García y Piccolo (2004) para la identificación de la brisa marina. Se analizaron datos meteorológicos de temperatura, humedad y viento obtenidos de la estación ubicada en el balneario. Se complementó el estudio con el análisis de mapas sinópticos e imágenes satelitales. Se identificaron 40 días con brisas de mar cuya mayor frecuencia se evidenció durante el verano con 18 casos. El mes de julio no presentó brisas durante el periodo analizado. Las brisas marinas predominaron del sector ESE y SE. Su duración promedio fue de dos horas y media. La velocidad media de las brisas marinas fue 4.5 m s-1.; Les brises marines sont phénomènes météorologiques à l’échelle locale qu’ils exercent son influence sur la côte pendant toute l’année, cependant ils sont peu abondants, les travaux réalisés sur la côte argentine. L’objectif de la recherche présente est de caractériser et de déterminer la circonstance des brises de mer dans Monte Hermoso, la station balnéaire placée dans le sud-ouest de la Province du Buenos Aires (61º15‘55“W, 38º59‘3”S). La période analysée comprend du décembre 2007 à un juillet 2010. Elle s’est appliquée, la méthodologie proposée par Zubillaga et Piccolo (1977/78a) et García et Piccolo (2004) pour l’identification de la brise marine. On a analysé des données météorologiques de température, d’humidité et de vent obtenues de la station placée dans la station balnéaire. L’étude s’est complétée avec l’analyse de cartes synoptiques et d’images satelitales. Ils se sont identifiés 40 jours aux brises de mer dont la plus grande fréquence a été manifeste durant l’été avec 18 cas. Un juillet il n’a pas présenté de brises durant la période analysée. Les brises marines ont prédominé du secteur c’et. Sa durée milieu a été de deux heures et demie. La vitesse moyenne des brises marines a été 4.5 m s-1.

Funciones ejecutivas en niños escolarizados: efectos de la edad y del estrato socioeconómico; Executive functions in school-aged children: age and socioeconomic status effects Arán Filippetti, Vanessa En los últimos años, se ha incrementado notoriamente el estudio sobre las funciones ejecutivas prefrontales en niños de edad escolar. El objetivo del presente estudio es analizar la influencia de la edad y del estrato socioeconómico (ESE) en el desempeño de tareas ejecutivas y conocer cuáles son las variables socioeconómicas que predicen una mejor ejecución. Participaron 254 niños de 7 a 12 años de edad de diferentes estratos socioeconómicos de la ciudad de Santa Fe, Argentina. Se utilizó una batería de pruebas ejecutivas sensibles a la función prefrontal. Los resultados obtenidos señalan un efecto significativo de la edad y del ESE sobre las funciones ejecutivas estudiadas. Los diferentes dominios del constructo siguen una trayectoria diferente según el desarrollo y el efecto del ESE. Además, en todas las funciones ejecutivas se evidencia un patrón de funcionamiento cognitivo inferior en los niños de estrato socioeconómico bajo (ESB). Finalmente, se encontró que, de las variables incluidas en el análisis, solo el nivel educativo de la madre y las condiciones de alojamiento de la familia se asocian al funcionamiento ejecutivo de los niños. Se discuten los resultados en función de la influencia que ejerce la maduración cerebral y las variables ambientales en el funcionamiento ejecutivo.

A matter of history: effects of tourism on physiology, behaviour and breeding parameters in Magellanic Penguins (Spheniscus magellanicus) at two colonies in Argentina Villanueva, María Cecilia; Walker, Brian G.; Bertellotti, Néstor Marcelo Increasing ecotourism activity in Argentine Patagonia has led to concerns about the effects of ecotourism on wildlife populations. Penguin breeding colonies are popular tourist destinations. While some species of penguins habituate to human visits, others exhibit negative effects due to disturbance. We studied the effects of tourism on Magellanic Penguins (Spheniscus magellanicus) at San Lorenzo colony located on the Peninsula Valdes, Chubut, Argentina. We measured behavioural, physiological, and reproductive parameters in birds nesting in tourist-visited and non-visited areas. San Lorenzo has 11 years of visitation history and a low intensity of visitors (~10,000 annually). After 15 min of a simulated tourist visit, penguins in the tourist area showed fewer alternate head turns and lower plasma levels of the stress hormone corticosterone than penguins in a non-visited area. However, penguins showed similar baseline levels of corticosterone between areas as well as similar levels of integrated corticosterone expressed after an acute stressor. Penguin breeding success and chick growth were similar between areas. We compared these findings to results previously published from Punta Tombo, a colony with a longer history (+50 years) and high intensity of annual visitors (>120,000 people). Many (reproductive and behavioural parameters), but not all (physiological parameters), of our findings are similar. That a physiological difference exists may suggest that the previous history of human visitation plays an important role in the response of the birds. Thus, the continuous monitoring of tourist activity is important, as a history of visitation disturbance seems to have an effect on how birds respond to tourists.

Numerical solution and validation concerning a descriptive model of a simultaneous heat and mass transfer process Villa Saravia, Luis Tadeo; Sanziel, Maria Cristina; Bouciguez, Angélica Carmen This paper deals with the numerical solution of an initial moving boundary problem (IMBVP) arising from a simplified version of a free boundary problem (IFBVP) which was formulated in another paper, as a mathematical model of heat and moisture transfer during the bubbling stage of an immersion frying process of stick shaped natural potato. The IMBVP was solved numerically using an explicit finite difference method, immobilizing the moving boundary through the use of the well known Landau transformation. The simulation output provides the temperature and moisture profiles and the amount of free moisture lost by vaporization. The model was validated by comparing the predicted results with experimental data. A good agreement was obtained.

Biogeochemical controls on the bacterial population in the eastern Atlantic Ocean Neogi, Sucharit Basu; Koch, Boris Peter; Schmitt Kopplin, Philippe; Pohl, Christine; Kattner, Gerhard; Yamasaki, Shintaro; Lara, Ruben Jose Little is known about bacterial dynamics in the oligotrophic ocean, particularly about cultivable bacteria. We examined the abundance of total and cultivable bacteria in relation to changes in biogeochemical conditions in the eastern Atlantic Ocean with special regard to Vibrio spp., a group of bacteria that can cause diseases in human and aquatic organisms. Surface, deep water and plankton (<20 µm, 20– 55 µm and >55 µm) samples were collected between 50◦ N and 24◦ S. Chlorophyll-a was very low (<0.3 µg l−1 ) in most areas of the nutrient-poor Atlantic, except at a few locations near upwelling regions. In surface water, dissolved organic carbon (DOC) and nitrogen (DON) concentrations were 64– 95 µM C and 2–10 µM N accounting for ≥90 % and ≥76 % of total organic C and N, respectively. DOC and DON gradually decreased to ∼45 µM C and <5 µM N in the bottom water. In the surface layer, culture independent total bacteria and other prokaryotes represented by 40 -6-diamidino- 2-phenylindole (DAPI) counts, ranged mostly between 107 and 108 cells l−1 , while cultivable bacterial counts (CBC) and Vibrio spp. were found at concentrations of 104–107 and 102–105 colony forming units (CFU) l−1 , respectively. Most bacteria (>99 %) were found in the nanoplankton fraction (<20 µm), however, bacterial abundance did not correlate with suspended particulates (chlorophyll-a, particulate organic C [POC] and N [PON]). Instead, we found a highly significant correlation between bacterial abundance and temperature (p < 0.001) and a significant correlation with DOC and DON (p < 0.005 and < 0.01, respectively). In comparison to CBC and DAPI-stained prokaryotes, cultivable Vibrio showed a stronger and highly significant correlation with DOC and DON (p < 0.0005 and p < 0.005, respectively). In cold waters of the mesopelagic and abyssal zones, CBC was 50 to 100-times lower than in the surface layer; however, cultivable Vibrio spp. could be isolated from the bathypelagic zone and even near the seafloor (average ∼10 CFU l−1 ). The depth-wise decrease in CBC and Vibrio coincided with the decrease in both DOC and POC. Our study indicates that Vibrio and other bacteria may largely depend on dissolved organic matter to survive in nutrient-poor oceanic habitats.

Producción y ambiente: beneficios mutuos Jobbagy Gampel, Esteban Gabriel; Mercau, Jorge L.; Baldi, Germán La conexión y los posibles conflictos que existen entre producir y proteger el ambiente no son una novedad para los productores agropecuarios. Reducir la erosión, sostener los niveles de materia orgánica del suelo o mantener especies valiosas del pastizal son metas presentes desde hace décadas y que han obligado a resolver dilemas entre rentabilidad inmediata y ambiente; disyuntivas que cuando se materializan en nuestro lote agregan el enorme incentivo de proteger un recurso propio. Pero la relación producción-ambiente se torna compleja y polémica cuando miramos más allá y comprendemos el papel que desempeña la porción de territorio que manejamos sobre la generación de productos y de valores ambientales que reclama la sociedad.

Primer canto argentino de Raúl González Tuñón: volver a la Patria para "meterse" Alle, María Fernanda El presente trabajo analiza el libro de Raúl González Tuñón publicado en el año 1945, a su regreso al país después de cinco años de residencia en Chile, Primer canto argentino. Este poemario debe ser pensado en el contexto que lo sitúa a caballo de dos acontecimientos centrales que signan la vida política y social del país: el 17 de octubre y las elecciones del año 46, puesto que es este contexto el que reviste de importancia y significación a los poemas. El propósito de este trabajo será desentrañar varios interrogantes que se fundan en las contradicciones, las paradojas y los recortes que presenta la versión de la historia narrada por González Tuñón puesto que, en ese contexto signado por la emergencia del peronismo, los poemas de Tuñón narran una versión triunfante de la historia nacional, recuperando el relato histórico construido por el PCA, que supone la victoria final sobre las fuerzas “nazifascistas”. Al mismo tiempo, el trabajo indaga la imagen de escritor que construye Raúl González Tuñón en este poemario en el cruce de dos linajes –el de los opositores y el de los poetas civiles– y que es posible llamar voz convocante.

Statistical optimization of influenza H1N1 production from batch cultures of suspension Vero cells (sVero) Paillet, Cristian; Forno, Guillermina; Soldano, Nicolas; Kratje, Ricardo Bertoldo; Etcheverrigaray, Marina Efficient vaccine production requires the growth of large quantities of virus produced with high yield from a safe host system. Human influenza vaccines are produced in embryonated chicken eggs. However, over the last decade many efforts have allowed the establishment of cell culture-derived vaccines. We generated a Vero cell line adapted to grow in suspension (sVero) in a serum-free medium and evaluated it for its potential as host cell for influenza vaccine production. Initially we studied the capacity of sVero cells to grow in the presence of incremental concentrations of trypsin. In comparison with adherent Vero cells (aVero), we found that sVero cells maintain their growth kinetics even with a threefold increase in trypsin concentration. The influence of the conditions of infection on the yield of H1N1 produced in serum-free suspension cultures of sVero cells was investigated by a 22 full factorial experiment with center point. Each experiment tested the influence of the multiplicity of infection (m.o.i.) and trypsin concentration, on production yields at two levels, in four possible combinations of levels and conditions, plus a further combination in which each condition was set in the middle of its extreme levels. On the basis of software analysis, a combination of m.o.i. of 0.0066 TCID50%/cell and trypsin concentration of 5 g/1.0 × 106 cells with a desirability of 0.737 was selected as the optimized condition for H1N1 production in sVero cells. Our results show the importance of proper selection of infection conditions for H1N1 production on sVero cells in serum-free medium.

Trabajo infantil y pobreza de los hogares en la Argentina; Child labor and household poverty in Argentina Paz, Jorge Augusto; Piselli, Carolina El modelo de Basu y Van (1998) plantea a nivel teórico la llamada hipótesis de lujo según la cual los hogares están comandados por padres altruistas y pobres que recurren al trabajo infantilcomo estrategia deescape dela pobreza. Según esteenfoque, si la economía está en una situación deequilibrio múltiple, puede ocurrir quela aplicación efectiva de las leyes que prohíben el trabajo infantil provoque un empeoramiento del bienestar delos hogares y aumentela pobreza. Con datos dela Encuesta de Actividades de Niños, Niñas y Adolescentes realizada en la Argentina en 2004, seexplora empíricamentela hipótesis de padres altruistas examinando en qué medida la pobreza monetaria y las privaciones materiales pueden considerarse determinantes de la participación económica de niñas, niños y adolescentes.; The model of Basu and Van (1998) presents, at a theoretical level, the so-called luxury hypothesis, according to which households are headed by altruistic and poor parents who recur to child labor as a strategy to escape poverty. This focus states that if theeconomy is in a situation of multiple equilibrium, it may happen that the effective application of laws prohibiting child labor lead to a worsening of household welfare and an increasein poverty. Using data from the Activities of Boys, Girls and Adolescentscarried out in Argentina in 2004, weexploreempirically the altruistic parent hypothesis,examining how monetary poverty and material privation can be considered determinants of economic participation by girls, boys and adolescents.

La bioética como entrenamiento y facilitadora de la influencia de agentes católicos en el espacio público en Argentina Irrazabal, María Gabriela En este trabajo describo ciertas acciones que llevan a cabo algunos agentes religiosos del catolicismo para, según manifiestan explícitamente, impedir el pleno acceso y la ampliación de derechos en materia de salud sexual y reproductiva. A partir del análisis de un curso de entrenamiento en bioética y una acción de lobby parlamentario intento plantear interrogantes sobre la influencia de la institución católica en el espacio público argentino. Asimismo, tomando datos de encuestas recientes, ilustró la tensión existente entre los lineamientos de las jerarquías eclesiásticas y las prácticas y opiniones sobre salud sexual y reproductiva de la feligresía femenina. Mi propósito es plantear la heterogeneidad presente dentro del catolicismo respecto a estos temas y analizar su expresión en el espacio público.

Six new species of Dasyhelea (Insecta, Diptera, Ceratopogonidae) from Patagonia; Seis especies nuevas de Dasyhelea (Insecta, Diptera, Ceratopogonidae) de la Patagonia Diaz, Maria Florentina; Spinelli, Gustavo Ricardo; Ronderos, Maria Marcela Six new species of Dasyhelea Kieffer, 1911 from Argentinean and Chilean Patagonia are described and illustrated based on adults. Five of these species do not belong to any of the recognized groups found in the Americas. The remaining one, Dasyhelea pabloi sp. nov. is a typical member of the leptobranchia group and is the first record of a species from this group found in the Neotropical region; Se describen e ilustran seis especies nuevas de Dasyhelea Kieffer, 1911 de la Patagonia argentina y chilena. Cinco de estas especies no pertenecen a ninguno de los grupos reconocidos para América. La especie restante, Dasyhelea pabloi sp. nov. es un miembro típico del grupo leptobranchia, lo que representa el primer registro en la Región Neotropical de una especie perteneciente a este grupo.

Cellular and molecular actions displayed by estrone on vascular endothelium Rauschemberger, María Belén; Sandoval, Marisa Julia; Massheimer, Virginia Laura In this work we provide evidence that estrone “per se” modulates cellular endothelial growth and survival, events that play key roles in the development of vascular disease. Moreover, under oxidative stress conditions the hormone prevented apoptosis triggered by hydrogen peroxide. Although estrone did not affect E-selectin and VCAM-1 mRNAs synthesis, the hormone prevented the expression of these adhesion molecules induced by the proinflammatory agent LPS. The steroid partially attenuated leukocyte adhesion not only under basal conditions but also in the presence of LPS. Using ICI182780 compound as estrogen receptor antagonist, and PD98059 as MAPK inhibitor we obtained evidence that the mitogenic action of estrone involved the participation of ER and MAPK transduction pathway activation. The presence of estradiol impaired the effect of estrone on cell proliferation and vasoactive production. These results suggest that estrone exhibits a remarkable biological action on endothelial cells, modulating vasoactive production, proliferation, apoptosis, and cell adhesion events.

Un marco teórico para la investigación jurídica Pezzetta, Silvina El presente artículo tiene como objetivo la utilización de algunos parámetros epistemológicos para distinguir los tipos de trabajos que producen los estudiosos y estudiosas del derecho. Parto de la idea de que un trabajo que pretenda ser considerado como parte de las ciencias sociales no puede carecer de un marco teórico completo, es decir, con tres niveles de abstracción: paradigma, teoría general y teoría sustantiva. Para conseguir los fines propuestos describo algunas características propias del campo de producción jurídica y las dificultades que existen para articular teoría, metodología y objetivos.; The goal of this article is to apply some epistemological concepts in order to classify the papers produced by law researchers. To do that I assume that every social research needs a complete theoretical framework. Law research can avoid this requirement if the intention is to be considered as a social research work. With the intention of complete the objectives; I describe the particular features of the field of juridical production and the difficulties to articulate theory, methodology and specific objectives.

Una Plataforma para la salud : contra las alergias alimentarias Gonzalez, Claudia Beatriz Las alergias alimentarias son inmunopatologías cuya incidencia se incrementa cada vez más. Según un informe realizado por la Organización Mundial de la Salud (OMS) y la Organización para la Alimentación y la Agricultura de las Naciones Unidas (FAO, por sus siglas en inglés), la prevalencia estimada de este tipo de alergias en la población general es del “uno al tres por ciento en los adultos y del cuatro al seis por ciento en los niños”. En los Estados Unidos, por ejemplo, afecta al 3,5 por ciento de la población, mientras que en la Argentina se habla de un cuatro por ciento (aunque no existen estudios científicos que corroboren esta información). Si bien el riesgo de muerte por casos de alergia es bajo, existen determinados alérgenos alimentarios cuya probabilidad de desencadenar reacciones anafilácticas es importante. En estos casos, si no se cuenta con una intervención médica inmediata, el problema puede transformarse en una reacción severa y hasta fatal. ...

Inertial Density Currents over Porous Media Limited by Different Lower Boundary Conditions Thomas, Luis Pablo; Marino, Beatriz Maria We study the evolution of two-dimensional high-Reynolds-number density currents propagating over horizontal porous substrates initially saturated with a lighter fluid when an impermeable surface under the bed is used and a Darcy flow through the medium takes place. Laboratory experiments were performed varying the initial characteristic parameters such as the volume released, the height-to-width ratio of the dense fluid, the relative density difference between the current and ambient fluids, and the bed depth. The dynamic changes of the gravitydriven flow and the influence of the thickness of the porous substrate are described by means of an empirical analysis that considers two lower boundary conditions of the bed, that is, when it is bounded from below by an impermeable or a permeable layer. Thus, the new experimental results are integrated to previous findings in a unified theoretical treatment. In the present case, the dense fluid penetrates into the porous layer pushing the lighter one through the upper boundary located ahead of the current, as shown by the vorticity distribution, and modifying the interaction between the flows over and inside the bed. This flow in the neighborhood of the front, although important, is smaller than the one that would pass through the lower boundary if this were permeable.