Viscosity of supercooled aqueous glycerol solutions, validity of the Stokes-Einstein relationship, and implications for cryopreservation Trejo González, José Adolfo; Longinotti, María Paula; Corti, Horacio Roberto The viscosity of supercooled glycerol aqueous solutions, with glycerol mass fractions between 0.70 and 0.90, have been determined to confirm that the Avramov-Milchev equation describes very well the temperature dependence of the viscosity of the binary mixtures including the supercooled regime. On the contrary, it is shown that the free volume model of viscosity, with the parameters proposed in a recent work (He, Fowler, Toner, J. Appl. Phys. 100 (2006) 074702), overestimates the viscosity of the glycerol-rich mixtures at low temperatures by several orders of magnitude. Moreover, the free volume model for the water diffusion leads to predictions of the Stokes-Einstein product, which are incompatible with the experimental findings. We conclude that the use of these free volume models, with parameters obtained by fitting experimental data far from the supercooled and glassy regions, lead to incorrect predictions of the deterioration rates of biomolecules, overestimating their life times in these cryopreservation media. © 2012 Elsevier Inc.

Metamorphic evolution of the Río de la Plata Craton in the Cinco Cerros area, Buenos Aires Province, Argentina Massonne, Hans-Joachim; Dristas, Jorge Anastasio; Martinez, Juan Cruz A metapelite and an interlayered granite were studied from the Cinco Cerros area ca. 65 km WNW of the city of Mar del Plata. Garnet in these samples is slightly zoned with core and rim compositions of pyr 17(gro + andr) 6spes 1.5alm 75.5 and pyr 13.5(gro + andr) 5.5spes 2alm 80, respectively, in the metapelite. Corresponding compositions in the granite are pyr 15(gro + andr) 3.5spes 3.5alm 78 and pyr 11(gro + andr) 3.5spes 4.5alm 81. We used the PERPLE_X computer software package to calculate P-T pseudosections. From the pseudosection of the metapelite P-T conditions of 6.7 kbar and 670 °C were derived for an early metamorphic stage. Subsequently, a pressure release occurred at decreasing temperatures. The final metamorphic P-T conditions recorded by the studied rock are 4.5 kbar and 600 °C compatible with the absence of cordierite, staurolite, and an Al 2SiO 5-phase. Garnet in the granitoid crystallized between 715 and 690 °C at a pressure around 7.7 kbar.U-Th-Pb age dating with the electron microprobe was performed. 16 analyses of monazite in the metapelite formed three clusters resulting in ages of I: 2073 ± 11.4 (1 σ) Ma, II: 1913 ± 11.0 (1σ) Ma, and III: 1805 ± 20.8 (1 σ) Ma. Thus, the Paleoproterozoic metamorphic event can be related to the Trans-Amazonian cycle and was followed by slow cooling.As our study area is close to the margin of the Río de la Plata Craton, where abundant magmatic arc-derived plutonic rocks are outcropping, we interpret the derived P- T data as follows: A heating event (not recorded by the studied rocks) resulted from magmas that intruded during the Trans-Amazonian cycle. This event was followed by slow exhumation, probably caused by erosion, accompanied by thermal relaxation. © 2012 Elsevier Ltd.

Cultivos agrícolas y su rol como reservorios de carbono y fuentes de energía Manrique, Silvina Magdalena; Franco, Ada Judith El objetivo del presente trabajo fue analizar el potencial de la biomasa residual agrícola generada desde las principales producciones del municipio de Coronel Moldes, provincia de Salta (ají, tabaco Criollo y tabaco Virginia) en cuanto a la mitigación de GEI responsables del sobrecalentamiento de la atmósfera. Se consideraron dos estrategias generales de mitigación: i) como reservorio de carbono (C) y ii) como fuente de energía renovable neutra en emisiones de C, que sustituiría parcialmente a los combustibles fósiles empleados. Se evaluó este potencial en relación con otras fuentes de biomasa para las cuales existían estudios previos en la zona. Si bien su aporte como reservorio de C no es permanente, permite dimensionar su contribución en relación a la biomasa natural de la zona. En cuanto fuente de energía, el empleo de esta biomasa posibilitaría evitar cerca de 500 tCO2/año (emisiones anuales de 90 ciudadanos) con beneficios económicos y ambientales.

Second harmonic generation microscopy as a powerful diagnostic imaging modality for human ovarian cancer Adur, Javier Fernando; Pelagati, Vitor B.; de Thomaz, Andre A.; Baratti, Mariana O.; Andrade, Liliana A. L. A.; Carvalho, Hernandes F.; Bottcher Luiz, Fátima; Lenz Cesar, Carlos In this study we showed that second-harmonic generation (SHG) microscopy combined with precise methods for images evaluation can be used to detect structural changes in the human ovarian stroma. Using a set of scoring methods (alignment of collagen fibers, anisotropy, and correlation), we found significant differences in the distribution and organization of collagen fibers in the stroma component of serous, mucinous, endometrioid and mixed ovarian tumors as compared with normal ovary tissue. This methodology was capable to differentiate between cancerous and healthy tissue, with clear cut distinction between normal, benign, borderline, and malignant tumors of serous type. Our results indicated that the combination of different image-analysis approaches presented here represent a powerful tool to investigate collagen organization and extracellular matrix remodeling in ovarian tumors.

Contribution of proteomics for diving into the lactic acid bacteria role and the modification of the food matrix during fermentation Fadda, Silvina G. Fermentation and drying can be considered as the oldest ways to preserve raw materials extending the shelf-life as well as enhancing the flavour and nutritional qualities of the products. Lactic acid bacteria (LAB) are the main agents responsible for fermentation, reducing the ripening time, minimizing manufacturing defects, improving sensory properties and inhibiting the development of pathogenic and spoilage flora. LAB is also considered as the most important microorganism responsible for the health-promoting effects of fermented foods, especially in milk-derived products. Indeed, strains of some species have traditionally been used as probiotics and added as functional bacteria in various food commodities [1]. Due to the huge economic significance of industrial application of LAB as starters, biopreservatives and probiotics, a research emphasis on their metabolism, genetic and applications has been placed in the last 25 years [2].

Application of bacteriocinogenic Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch in the control of Listeria monocytogenes in fresh Minas cheese Vera Pingitore, Esteban; Todorov, Svetoslav Dimitrov; Sesma, Fernando Juan Manuel; Franco, Bernadette Dora Gombossy de Melo Several strains of Enterococcus spp. are capable of producing bacteriocins with antimicrobial activity against important bacterial pathogens in dairy products. In this study, the bacteriocins produced by two Enterococcus strains (Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch), isolated from cheeses, were characterized and tested for their capability to control growth of Listeria monocytogenes 426 in experimentally contaminated fresh Minas cheese during refrigerated storage. Both strains were active against a variety of pathogenic and non-pathogenic microorganisms and bacteriocin absorption to various L. monocytogenes, Enterococcus faecalis ATCC 19443 and Lactobacillus sakei ATCC 15521 varied according to the strain and the testing conditions (pH, temperature, presence of salts and surfactants). Growth of L. monocytogenes 426 was inhibited in cheeses containing E. mundtii CRL35 up to 12 days at 8 C, evidencing a bacteriostatic effect. E. faecium ST88Ch was less effective, as the bacteriostatic affect occurred only after 6 days at 8 C. In cheeses containing nisin (12.5 mg/kg), less than one log reduction was observed. This research underlines the potential application of E. mundtii CRL35 in the control of L. monocytogenes in Minas cheese.

Actividad antimicrobiana de películas comestibles elaboradas a base de proteínas del lactosuero y glicerol incorporadas con sales orgánicas Perez, Leonardo Martin; Soazo, Marina del Valle; David, Mauricio; Rubiolo, Amelia Catalina; Verdini, Roxana Andrea El empleo de películas comestibles formuladas con compuestos antimicrobianos para recubrir alimentos es una forma de “envasado activo”. Mediante esta tecnología, se busca extender la vida útil de un producto alimenticio y disminuir la tasa de contaminación microbiana favoreciendo la seguridad de los consumidores. Los ácidos orgánicos y sus sales han sido utilizados ampliamente como aditivos alimenticios para controlar el desarrollo de patógenos y evitar la diseminación de enfermedades. En el presente trabajo, se evaluó el potencial antimicrobiano de películas comestibles elaboradas a base de proteínas del lactosuero (WPC) y glicerol (Gli) con la incorporación de sorbato de potasio (SP), benzoato de sodio (BS) y propionato de sodio (PS) frente a la cepa shigatoxigénica Escherichia coli O157:H7 ATCC 43895. La incorporación de las sales orgánicas en las películas ácidas de WPC/Gli obtenidas a pH 5,2 se realizó en cuatro concentraciones: 0,25%, 0,50%, 0,75% y 1,0% p/p. La actividad antimicrobiana se evaluó en medio agar Mueller-Hinton regulado a pH 5,2 a través de ensayos de difusión en agar y pruebas de barrera (cualitativa y cuantitativa). Además, se estudió la relación entre la capacidad antimicrobiana de las películas y la concentración de inóculo bacteriano (alto y bajo). El ensayo de difusión mostró que la incorporación de SP y BS a las películas comestibles de WPC/Gli redujo o inhibió el crecimiento de E. coli, excepto cuando la concentración de SP fue 0,25%. Este efecto fue más notorio a medida que la concentración de sales orgánicas en las películas aumentó y más evidente a inóculo bajo del patógeno. No se observó inhibición alguna ante la incorporación de PS en las películas. Los resultados de las pruebas de barrera cualitativa revelaron que tanto el SP como el BS a concentraciones iguales o superiores a 0,50% presentan excelentes propiedades para prevenir la contaminación externa, no siendo efectiva la adición de PS a las concentraciones ensayadas. Los resultados de las pruebas de barrera cualitativa y cuantitativa fueron coherentes con los obtenidos en los ensayos de difusión en agar. En conclusión, la adición de SP y BS a películas comestibles ácidas de WPC/Gli puede ser de suma utilidad para prevenir la contaminación post-proceso de los alimentos, demostrando un amplio potencial para su aplicación como recubrimiento activo en la industria alimentaria.

Direct and indirect photodynamic therapy effects on the cellular and molecular components of the tumor microenvironment Milla Sanabria, Laura Natalia; Rodriguez, Matias Exequiel; Cogno, Ingrid Sol; Rumie Vittar, Natalia Belen; Pansa, Maria Florencia; Lamberti, María Julia; Rivarola, Viviana Photodynamic therapy (PDT) is a novel cancer treatment. It involves the activation of a photosensitizer (PS) with light of specific wavelength, which interacts with molecular oxygen to generate singlet oxygen and other reactive oxygen species (ROS) that lead to tumor cell death. When a tumor is treated with PDT, in addition to affect cancer cells, the extracellular matrix and the other cellular components of the microenvironment are altered and finally this had effects on the tumor cells survival. Furthermore, the heterogeneity in the availability of nutrients and oxygen in the different regions of a tridimensional tumor has a strong impact on the sensitivity of cells to PDT. In this review, we summarize how PDT affects indirectly to the tumor cells, by the alterations on the extracellular matrix, the cell adhesion and the effects over the immune response. Also, we describe direct PDT effects on cancer cells, considering the intratumoral role that autophagy mediated by hypoxia-inducible factor 1 (HIF-1) has on the efficiency of the treatment.

The effect of an invading filter-feeding bivalve on a phytoplankton assemblage from the Parana´ system: a mesocosm experiment Frau, Diego; Rojas Molina, Florencia Mercedes; Devercelli, Melina; Jose, Susana Beatriz The effect of different concentrations of the bivalve Limnoperna fortunei on the algal density and structure and its filtration rate was estimated in a mesocosm experiment. The experiment was carried out using containers of 200 L and three treatments: Control (without bivalves), C1 (with 128 individual bivalves), and C2 (with 256 individual bivalves). Decrease in phytoplankton density was detected in bivalve treatments after 6 h. A decrease of 52% and 86% of the initial density was measured in C1 and C2, respectively, after 48 h. All algae groups showed substantial decrease in densities (>60%) and the composition of the algae assemblages changed in the presence of the bivalve. In particular, there was an increase in the density of Flagellates. The maximum estimated bivalve filtration rate was 357 mL ind−1 h−1 at 28°C. Our results suggest that the invading bivalves could significantly affect both the plankton density and assemblage structure in natural systems.

Enzyme proteolysis enhanced extraction of ACE inhibitory and antioxidant compounds (peptides and polyphenols) from Porphyra columbina residual cake Cian, Raúl Esteban; Alaiz, Manuel; Vioque, Javier; Drago, Silvina Rosa The traditional method to obtain phycocolloids from seaweeds implies successive extraction steps with cold and hot water. The residual cake derived from phycocolloids obtaining process of red seaweed Porphyra columbina is a waste containing 27 % protein and 10.7-mg gallic acid equivalents (100 g)−1. Seaweeds contain functional proteins, and the enzymatic hydrolysis of these proteins has been shown to release bioactive peptides. The aims of this study were to extract bioactive peptides and polyphenols after enzymatic hydrolysis of the residual cake and to evaluate their ACE inhibitory and antioxidant capacities (TEAC, DPPH, and copper-chelating activity). Residual cake hydrolysate has low molecular weight peptides containing Asp, Glu, Ala, and Leu. Residual cake hydrolysate had higher protein solubility than residual cake. ACE inhibition (≈45 %) and radical scavenging activity (TEAC and DPPH inhibition) were attributed mainly to low molecular weight peptides (500 Da) and polyphenols compounds released during proteolysis. The 50 % inhibition protein concentration value (IC50) corresponded to residual cake hydrolysate was 1.01 ± 0.02 and 0.91 ± 0.01 g L−1, for ABTS and DPPH, respectively. Also, residual cake hydrolysate had high copper-chelating activity (≈97.5 %). Hydrolysis could be used as a means to obtain ACE inhibitory and antioxidant compounds (peptides and polyphenols) from algae protein waste and add value to the phycocolloids extraction process.

Production of fibronectin binding protein A at the surface of lactococcus lactis increases plasmid transfer In vitro and in vivo Pontes, Daniela Santos; Innocentin, Silvia; del Carmen, Silvina Andrea; Franco Almeida, Juliana; Leblanc, Jean Guy Joseph; de Moreno, Maria Alejandra; Blugeon, Sébastien; Cherbuy, Claire; Lefèvre, François; Azevedo, Vasco; Miyoshi, Anderson; Langella, Philippe; Chatel, Jean-Marc Lactococci are noninvasive lactic acid bacteria frequently used as protein delivery vectors and, more recently, as DNA delivery vehicles. We previously showed that Lactococcus lactis (LL) expressing the Fibronectin-Binding Protein A of Staphylococcus aureus (LL-FnBPA+) showed higher internalization rates in vitro in Caco-2 cells than the native (wt) lactococci and were able to deliver a eukaryotic Green Fluorescent Protein (GFP) expression plasmid in 1% of human Caco-2 cells. Here, using the bovine beta-lactoglobulin (BLG), one of the major cow's milk allergen, and GFP we characterized the potential of LL-FnBPA+ as an in vivo DNA vaccine delivery vehicle. We first showed that the invasive strain LL-FnBPA+ carrying the plasmid pValac:BLG (LL-FnBPA+ BLG) was more invasive than LL-BLG and showed the same invasivity as LL-FnBPA+. Then we demonstrated that the Caco-2 cells, co-incubated with LL-FnBPA+ BLG produced up to 30 times more BLG than the Caco-2 cells co-incubated with the non invasive LL-BLG. Using two different gene reporters, BLG and GFP, and two different methods of detection, EIA and fluorescence microscopy, we showed in vivo that: i) in order to be effective, LL-FnBPA+ required a pre-coating with Fetal Calf Serum before oral administration; ii) plasmid transfer occurred in enterocytes without regard to the strains used (invasive or not); iii) the use of LL-FnBPA+ increased the number of mice producing BLG, but not the level of BLG produced. We thus confirmed the good potential of invasive recombinant lactic acid bacteria as DNA delivery vector in vivo.

The effect of administering equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) post artificial insemination on fertility of lactating dairy cows Bartolome, Julian; Perez Wallace, Santiago; de la Sota, Rodolfo Luzbel; Thatcher, W. W. The objective was to evaluate the effect of equine chorionic gonadotropin (eCG) and hCG post artificial insemination (AI) on fertility of lactating dairy cows. In Experiment 1, cows were either treated with eCG on Day 22 post AI (400 IU; n = 80) or left untreated (n = 84). On Day 29, pregnant cows were either treated with hCG (2500 IU; n = 32) or left untreated (n = 36). Pregnancy and progesterone were evaluated on Days 29 and 45. In Experiment 2, cows (n = 28) were either treated with eCG on Day 22 (n = 13) or left untreated (n = 15) and either treated with hCG on Day 29 (n = 14) or left untreated (n = 14). Blood sampling and ultrasonography were conducted between Days 22 and 45. In Experiment 3, cows were either treated with eCG on Day 22 post AI (n = 229) or left untreated (n = 241). Pregnancy was evaluated on Days 36 and 85. In Experiment 1, eCG on Day 22 increased (P < 0.02) the number of pregnant cows on Day 29 (50.0 vs. 33.3%) and on Day 45, the increase was higher (P < 0.01) in cows with timed AI (41.2 vs. 6.5%) than in cows AI at detected estrus (50.0 vs. 37.8%). Pregnancy losses were reduced by eCG and hCG, but increased in cows that did not receive eCG but were given hCG (P < 0.01). Treatment with hCG tended (P < 0.06) to increase progesterone in control cows, but not in cows treated with eCG. In Experiment 2, hCG increased (P < 0.01) the number of accessory CLs on Day 35 (28.5 vs. 0.0%) and tended (P < 0.07) to increase progesterone. In Experiment 3, eCG increased the number of pregnant cows (P < 0.05) on Days 36 and 85, but only in cows with low body condition (eCG = 45.6 and 43.5%; Control = 22.9 and 22.9%). In conclusion, eCG at 22 days post insemination increased fertility, primarily in cows with low body condition and reduced pregnancy losses when given 7 days before hCG; hCG induced accessory CLs and slightly increased progesterone, but hCG given in the absence of a prior eCG treatment reduced fertility. © 2012 Elsevier Inc.

Enamel formation genes influence enamel microhardness before and after cariogenic challenge Shimizu, Takehiko; Ho, Bao; Deeley, Kathleen; Briseño Ruiz, Jessica; Faraco, Italo M.; Schupack, Brett I.; Brancher, João A.; Pecharki, Giovana D.; Küchler, Erika C.; Tannure, Patricia N.; Lips, Andrea; Vieira, Thays C. S.; Patir, Asli; Yildirim, Mine; Poletta, Fernando Adrián; Mereb, Juan C.; Resick, Judith M.; Brandon, Carla A.; Orioli, Ieda Maria; Castilla, Eduardo Enrique; Marazita, Mary L.; Seymen, Figen; Costa, Marcelo C.; Granjeiro, José M.; Trevilatto, Paula C.; Vieira, Alexandre R. There is evidence for a genetic component in caries susceptibility, and studies in humans have suggested that variation in enamel formation genes may contribute to caries. For the present study, we used DNA samples collected from 1,831 individuals from various population data sets. Single nucleotide polymorphism markers were genotyped in selected genes (ameloblastin, amelogenin, enamelin, tuftelin, and tuftelin interacting protein 11) that influence enamel formation. Allele and genotype frequencies were compared between groups with distinct caries experience. Associations with caries experience can be detected but they are not necessarily replicated in all population groups and the most expressive results was for a marker in AMELX (p = 0.0007). To help interpret these results, we evaluated if enamel microhardness changes under simulated cariogenic challenges are associated with genetic variations in these same genes. After creating an artificial caries lesion, associations could be seen between genetic variation in TUFT1 (p = 0.006) and TUIP11 (p = 0.0006) with enamel microhardness. Our results suggest that the influence of genetic variation of enamel formation genes may influence the dynamic interactions between the enamel surface and the oral cavity.

“Informes no reservados”: Espacios de fuga virtuales de la Policía de la provincia de Buenos Aires Galvani, Mariana Cristina; Garriga Zucal, Jose Antonio; Melotto, Mariano Proponemos en este trabajo analizar los comentarios dejados por policías de la provincia de Buenos Aires en la página web: Informe reservado (informereservado.net). Esta página cuenta con un foro especial dedicado a los miembros de la Policía de la Provincia de Buenos Aires (PBBA), allí se ponen en discusión distintos aspectos referidos a la función policial. Abordamos este foro con el objeto de estudiar la constitución de espacios de discusión por parte de los policías, donde se cuestionan algunos valores institucionales tanto formales como informales y se refuerzan otros. La estructura institucional de la policía carece de espacios donde los oficiales y suboficiales puedan presentar sus desacuerdos, además sus leyes orgánicas les impiden peticionar colectivamente. Ante esta carencia el portal se presenta como uno de los medios alternativos que tienen los policías para expresarse respecto de la institución, los compañeros y los jefes.

A new species of liolaemus (Iguania: Liolaemidae) of the alticolor group from La Paz, Bolivia Ocampo Ballivian, Mauricio; Aguilar Kirigin, Álvaro J.; Quinteros, Andres Sebastian We describe a new species of Liolaemus, belonging to the alticolor group, that was previously confused with L. walkeri. The new species inhabits the inter-Andean dry valleys at two localities in the department of La Paz (Ananta and Jupapina), Bolivia. We compared the new species with 11 morphologically similar taxa classified as part of the alticolor group. Our comparisons were based on external morphology and included lepidosis, morphometry, meristic characters, and color patterns. Liolaemus sp. nov. differs from other species of the same group by unique dorsal coloration and lepidosis characteristics. © 2012 by The Herpetologists League, Inc.

"Podría ser así, o quizá todo lo contrario, o nunca existió" Futura: diseñando una utopía sensible Gatto, Ezequiel Guillermo En 1968 se presentó una obra de teatro experimental en el Instituto Di Tella, laboratorio artístico de las nuevas vanguardias estéticas urbanas. La peculiaridad de esta obra, dirigida por Alfredo Rodríguez Arias, extraía su fuerza escénica del conjunto de problemas planteados por el urbanismo. Mezcla de diagnóstico sobre las condiciones sociopolíticas de la vida en la ciudad y apuesta hacia el porvenir, un conjunto de reconocidas voluntades arquitectónicas formularon ciertos tópicos que luego se vieron expresados en Futura. Un cruce que daba cuenta de la fluida comunicación, en aquel período, entre arquitectura y prácticas estéticas, imaginando, en este caso, un tiempo por venir en el que la convivencia amistosa y recíproca reformularía las instituciones formales y las condiciones mismas de la vida en común.

La cadena del cuero en la Argentina: Tensiones estructurales, problemas de coyuntura y dilemas de la política en la posconvertibilidad; The leather chain in Argentina Schorr, Martín El comportamiento de la cadena de valor del cuero en la Argentina ha sido determinado por la rigidez estructural de su oferta y la legislación sectorial. Ambos aspectos tendieron a fortalecer el eslabón intermedio intensivo en capital y fabricante mayormente de commodities destinadas a la exportación, resultando en un segmento de manufacturas poco relevante. El sistema de incentivos sumado a la protección actual del mercado interno tiende a la sustitución en los bienes finales del cuero por otras materias primas que no gozan de ventajas comparativas y a la especialización en bienes de menor valor agregado en curtiembres. Sin embargo, es posible poner en marcha una serie de medidas de política que reviertan esta tendencia en pos del valor agregado y el empleo con orientación al mercado externo.; The behavior of the leather value chain in Argentina has been determined by the structural rigidity of its supply and the sectorial legislation. Both aspects have tended to strengthen the intensive intermediate link in capital and producer of commodities mostly for export, resulting in a small manufacturing segment with little relevance. The incentive system and the current protection of the domestic market tend to replace leather substitution with other raw materials in the final goods without comparative advantages and the specialization in lesser value added goods in tanneries. However, it is possible to start some policies to reverse this trend towards value added and employment orientated to the foreign market.

Sátira y filosofía en los studia humanitatis: La inluencia de Luciano y Epicuro en Lorenzo Valla, León Battista Alberti y Tomás Moro Vilar, Mariano Alejandro Durante el siglo XV el renovado interés en la recuperación de la cultura clásica trajo a la luz el De rerum natura de Lucrecio y las Vidas y opiniones de los filósofos más ilustres de Diógenes Laercio, lo que impulsó la nueva valoración del epicureísmo que ya había comenzado incluso antes de estos hallazgos. Simultáneamente, la utilización de los textos de Luciano de Samosata por parte de Manuel Crisoloras en sus cursos de griego en la ciudad de Florencia provocó una serie de imitaciones y reformulaciones del modelo satírico propuesto por este autor. En este trabajo analizaremos la forma en la que la influencia de Luciano fue útil para Lorenzo Valla, León Battista Alberti y Tomás Moro para darle forma a sus representaciones y reapropiaciones de la filosofía epicúrea y parodiar el ethos filosófico desde distintas perspectivas. Para esto nos concentraremos en el De vero falsoque bono (1433), el Momus sive principe (1450) y la Utopia (1516).; During the fifteenth century, the new interest in the recovery of the ancient culture brought to light the De rerum natura from Lucretius and the Lives and Opinions of Eminent Philosophersfrom Diogenes Laërtius. Both texts had an impact on the new interest in the epicurean sect, which had begun before this findings. At the same time, the utilization of texts from Lucian of Samosata by Manuel Chrysoloras in his Greek classes in the city of Florence provoked a series of imitations and reformulation of the satiric works of this author. In this article, we propose an analysis of the particular way in which Lorenzo Valla, Leon Battista Alberti and Thomas More used the satiric model from Lucian to present their representation and reformulation of the epicurean ideas, and to mock the philosophical ethos from different perspectives. From this point of view we will focus on three works: De vero falsoque bono (1433), Momus sive de principe (1450) and the Utopia (1516).

El rol de la democracia en la planificación urbana: caso ciudad de Rosario, Argentina (1983-1993); The role of democracy in urban planning: case Rosario city (1983-1993) Galimberti, Cecilia Inés La crisis del modelo de planificación tradicional ante la necesidad de abordar el territorio con una mirada cercana y directa a la “ciudad real”, analizada como un complejo sistema dinámico; trasciende internacionalmente en las esferas académicas, profesionales y administrativas. El presente artículo se propone analizar cómo ocurre este cambio de planificación en la ciudad de Rosario, Argentina; coincidente con la recuperación del gobierno democrático en 1983. La administración local democrática resignifica las ideas y debates en torno al rol de la arquitectura en la ciudad, ya establecidas desde finales de la década de 1970 en otras instituciones rosarinas como son la Facultad de Arquitectura y el Centro de Arquitectos Rosario; a fin de afrontar un nuevo compromiso frente al escenario contemporáneo de las demandas colectivas, reconociendo la caducidad de los instrumentos urbanísticos existentes de planificación. Es a partir de la articulación de diferentes actores en diversas instituciones, enriquecidos por la circulación internacional de nuevas ideas y estrategias urbanísticas, que se prefigura un cambio en la manera de soñar y transformar físicamente la ciudad; el cual se posibilita por el retorno de la democracia que permite la continuidad de políticas urbanas con lineamientos y objetivos esenciales de transformación de la ciudad basadas en el sentido colectivo de las necesidades sociales y en la actualización permanente del conocimiento de la ciudad real como el camino para construir cotidianamente el proyecto continuo de compromiso democrático.; The crisis of the traditional planning model before the need to approach the territory with a close and direct look to the "real city", analyzed as a complex dynamic system, goes beyond internationally in the academic, professional and administrative spheres. The present article attempts to analyze how this change takes place in the planning of the city of Rosario, Argentina, coinciding with the recovery of democratic government in 1983. Democratic local government redefines the ideas and debates on the role of architecture in the city, established since late 1970 in Rosario's other institutions such as the College of Architecture and the Center of Architects from Rosario in order to face a new commitment towards the contemporary scene of the collective demands, recognizing the expiration of the existing urban planning instruments. It is from the articulation of different actors in diverse institutions, enriched by the international flow of new ideas and planning strategies, that a change in the way of dreaming and physically transforming the city is foreshadowed, which is made possible by the return of democracy that allows the continuity of urban policies with essencial guidelines and targets of city transformation based on the collective sense of social needs and on the permanent updating of the real city knowledge as the way to build the ongoing project of democratic commitment.

Electrode and brain modeling in stereo-EEG Von Ellenrieder, Nicolás; Beltrachini, Leandro; Muravchik, Carlos Horacio Objective: To quantify the perturbation due to the presence of a measuring depth electrode on the intracranial electric potential distribution, and to study the effect of the heterogeneity and anisotropy of the brain tissues' electric conductivity. Methods: The governing differential equations are solved with the Boundary Elements Method to compute the perturbation on the electric potential distribution caused by the presence of the measuring electrode, and with the Finite Elements Method to simulate measurements in an heterogeneous anisotropic brain model. Results: The perturbation on the measured electric potential is negligible if the source of electric activity is located more than approximately 1. mm away from the electrode. The error induced by this perturbation in the estimation of the source position is below 1. mm in all tested situations. The results hold for different sizes of the electrode's contacts. The effect of the brain's heterogeneity and anisotropy is more important. In a particular example simulated dipolar sources in the gray matter show localization differences of up to 5. mm between homogeneous isotropic and heterogeneous anisotropic brain models. Conclusions: It is not necessary to include detailed electrode models in order to solve the stereo-EEG (sEEG) forward and inverse problems. The heterogeneity and anisotropy of the brain electric conductivity should be modeled if possible. The effect of using an homogeneous isotropic brain model approximation should be studied in a case by case basis, since it depends on the electrode positions, the subject's electric conductivity map, and the source configuration. Significance: This simulation study is helpful for interpreting the sEEG measurements, and for choosing appropriate electrode and brain models; a necessary first step in any attempt to solve the sEEG inverse problem. © 2012 International Federation of Clinical Neurophysiology.