Soil washing contaminated with heavy metals by using bacterial bioemulsifier at laboratory scale Castro, María Fernanda; Colin, Veronica Leticia; Amoroso, Maria Julia del R.; Villegas, Liliana Beatriz Heavy metal cannot be degradable into innocuous products and they tend to be strongly absorbed on the matrix of soils and sediments. These characteristics limit their solubilization and subsequent removal. An effective method to increase the metal-desorption of soil and sediments involves washing technologies assisted with surface active compounds as such bioemulsifiers. However, there is little information found in the literature regarding bacterial bioemulsfiers used for this purpose. In previous studies, it have being demonstrated the ability to produce bioemulsifier by an actinobacterium, Amycolatopsis tucumanensis DSM 45259, using different carbon and nitrogen sources. Also it was showed that both production and hence functional properties of bioemulsifier is associated mainly to carbon sources used for biosynthesis. Following these studies, the objective of the present work was to study the applicability of bioemulsifiers produced by A. tucumanensis DSM 45259 from different carbon a nitrogen sources, as washing agents in environmental remediation technologies, as well as to determine whether Cu(II) or Cr(VI) presence affecting the bioemuslfier production. To achieve this, soil samples were artificially contaminated with Cu(II) or Cr(VI) added as CuSO 4 .5H 2 O and K 2 Cr 2 O 7 , respectively, at final concentration of 200 mg kg −1 of soil. Washing experiments were performed using 2.0 g of contaminated soil in flasks. Soils were washed with 10 ml of aqueous solutions of the partially purified bioemulsifiers, using deionized water as control. Emulsification index of each bioemulsifier solution was previously adjusted to 60%. The washing procedures were performed by shaking at 30 ºC between 12 to 24 h. Soil samples were centrifuged at 10,000g and the concentration of Cu(II) and Cr(VI) in supernatants were analyzed by atomic absorption spectrometry and Cr(VI) concentration was measured using a colorimetric method. Under these assayed conditions, no significant Cu(II) removal could be detected after 12 h of washed either with H 2 Od or bioemulsifier solutions. However, A. tucumanensis bioemulsifiers seemed to be effective for Cr(VI) recovery, whose removal from soil increased 2 fold while compared to H 2 Od. Cr removed in the washing experiments remains in its hexavalent state. The increase of the in the washing time, did not improve the Cu(II) and Cr(VI) removal. Analysing the different effects of carbon and nitrogen sources and metal type, the last one was the most relevant variable that influence on the washing efficiency. In relation to the production of bioemulsifier by A. tucumanensis DSM 45259 in the presence of metals, the results showed that the assayed concentrations of Cu(II) and Cr(VI) (10, 20 and 30 ppm) in the culture media did not affect the bioemulsifier production. These are the first advances conducted in our research group focused on the direct application of microbial products in heavy metal remediation strategies.

A Neoproterozoic paleokarstic surface in the upper Villa Mónica Formation, Tandilia System, Argentina: Preliminary constraints on its origin and diagenesis Gómez Peral, Lucia; Poire, Daniel Gustavo; Sial, Alcides N.; Arrouy, Maria Julia The Neoproterozoic sedimentary successions of the Tandilia Basin are constituted by a wide range of sedimentary rocks. We analyse the upper section of the Villa M´onica Formation constituted almost entirely by dolostones. C-isotope pathways and mudstones with dropstones, just below the dolostones, suggest this succession is a probable cap carbonate. Therefore, the model of its diagenetic evolution is consistent with trends of primary marine origin. The age of this unit is still under debate, but stromatolites, Sr isotope data and δ 13C curve suggest Cryogenian age. An uplift registered on top of the formation is related to period of intense erosion and weathering with generation of a karstic surface over the dolostones as a telodiagenetic surface. This important unconformity was situated, from palaeomagnetic studies, in 595 Ma and is characterized by dedolomitization, intense dissolution and precipitation if iron oxide minerals, chert and calcite. Siliceous cementation and replacement have probably occurred when pH dropped during sub-aerial exposure associated to sea-level fall of uncertain relation with glaciations. This surface constitutes the contact between Villa M´onica and Colombo formations, representing an extensive period of erosion, and called “Piedra Amarilla surface”. A few meters below, further evolution of the dissolution processes developed a paleokarstic subsurface recognized by presence of up to 3 m caverns filled by weathered dolomite. C-O isotope data in this level are typical of meteoric fluids interaction showing lower with respect to unaltered dolostone, δ 13C varying from -0.45 to -1.87 and δ 18O VPDB from -6.16 to -10.25 .

El punk rock en Tucumán: un movimiento de cultura popular Mónaco, María Elvira Cuando observamos un fenómeno de cultura al que consideramos "popular", pensamos en ciertas características que éste tiene y que lo ubican dentro de lo que comúnmente llamamos "cultura popular". Esta simple operación crítica, no está sin embargo, libre de problemas. antes que nada porque pensar en fenómenos de cultura es sumamente complejo ya que abarcan dimensiones múltiples de la vida social. porque son históricos y situados, esto es, dependen de su lugar y tiempo, tanto en su realización como en su análisis. y por lo tanto, nuestras observaciones merecerán siempre una justificación y una continua revisión. Nos nos sirve tomar un concepto, definirlo y aplicarlo a la realidad a la manera de una grilla de referencia.Y porque además el concepto "popular", como categoría de análisis, fue tomando a lo largo de la historia, diferentes significados y fue usado para designar diferentes realidades. Se agrupa además en una familia de conceptos que se forma con "pueblo", "cultura popular", "popularidad", que si bien están emparentados unos con otros en sus usos, plantean la problemática de que, utilizados desde perspectivas diversas, se refieren a realidades diferentes de lo social.En ocasión de este ensayo, lo que pretendemos es observar un fenómeno de cultura que se considera de carácter popular y que es uno de los más significativoas de la escena cultura actual de Tucumán. Pero tratando de pensar en cómo y por qué lo consideramos y clasificamos de esta manera, esto es, pensando en el uso que "popular" tiene en nuestra comunidad y en este caso. Nos proponemos observar un movimiento cultural que tiene en nuestra región casi 40 años desarrollándose, que representa uno de los aspectos fuertes de la cultura local y que es considerado y nombrado como un movimiento de cultura popular: nos referimos al movimiento punk rock.

Resistencia o clientelismo: Imágenes de la política popular a la luz de diciembre de 2001 Quirós, Julieta El artículo reflexiona sobre un conjunto de imágenes que fueron desplegadas, al calor de los hechos de diciembre de 2001, en el marco de un debate político, mediático y académico, que tuvo por objeto definir las disposiciones que habrían guiado la participación de un actor específico: los sectores populares. A partir de esa reflexión, y en diálogo con mis investigaciones etnográficas sobre experiencias de politización en el Gran Buenos Aires, discuto algunas implicancias cognoscitivas y políticas de una serie de prácticas de conocimiento enraizadas en el estudio y debates de la politicidad de los sectores populares de la última década, atendiendo al carácter al mismo tiempo dinámico y recurrente de dos imágenes morales de la política.

La frontera argentino-chilena como espacio social en la Patagonia: balance de una historiografía renovada Bandieri, Susana Ofelia Cuando se habla de Estado nacional, concepto por demás complejo que involucra una variedad de cuestiones, comúnmente se hace referencia casi inmediata a uno de sus atributos más visibles: el control de un territorio definido por fronteras, que además se entienden como límites con otros Estados nacionales. Ahora bien, si se piensa en la historia nacional argentina y, dentro de ella, en la región patagónica, la cuestión de los límites jurídicos aparece recién como preocupación definitiva de los gobiernos en la segunda mitad del siglo XIX, cuando las instituciones nacionales, en pleno proceso de consolidación, decidieron extender coercitivamente sus dominios sobre la sociedad indígena, hasta entonces soberana de esos territorios, ampliando una frontera interna móvil y permeable que impedía hasta entonces la expansión agraria que exigía la plena incorporación del país al mercado internacional. La nacionalización del territorio implicó entonces el avance de las formas de ejercicio del poder sobre nuevos espacios del norte y sur del país -definidos desde entonces como Territorios Nacionales (en directa alusión a la "falta de madurez política" para su incorporación definitiva como provincias argentinas).

El espécimen más completo de Peltephilidae Ameghino (Mammalia, Xenarthra, Cingulata): Aportes sistemáticos Gonzalez Ruiz, Laureano Raul; Ciancio, Martin Ricardo; Gois Lima, Flavio Los Peltephilidae (Eoceno temprano–Mioceno tardío) son un grupo peculiar de armadillos, con numerosas características particulares, como la presencia de un par de osteodermos cefálicos nasales con forma de “cuernos”. Se han reconocido 5 géneros y 16 especies, a partir de osteodermos o de cráneos aislados respectivamente, lo que ha llevado a confusiones al momento de asignar nuevos especímenes. Además, la morfología de la coraza de los Peltephilidae es desconocida (a excepción del escudo cefálico). El nuevo espécimen (MPEF-PV 3011) que determinamos como Peltephilus pumilus Ameghino, colectado por el equipo del Museo Paleontológico “Egidio Feruglio” en Formación Santa Cruz (Mioceno temprano tardío), aflorante en la costa atlántica santacruceña, es el más completo peltefílido conocido. Sus restos incluyen cráneo y mandíbula, mayor parte del escudo cefálico, gran parte de la coraza dorsal, y restos de postcráneo (parte de la escápula, fémur y autopodio derechos, pelvis, vértebras lumbares y torácicas, y algunas costillas). En la coraza dorsal se contabilizan 27 hileras móviles (la porción preservada no ofrece evidencias de escudo escapular) y 4 hileras correspondientes a la región anterior del escudo pélvico. Dado el escaso número de especímenes que preservan restos craneomandibulares asociados con osteodermos articulados de la coraza dorsal, este espécimen adquiere especial relevancia para conocer la estructura de la coraza dorsal, analizar la variación de los osteodermos a lo largo de la misma y verificar la validez de especies reconocidas por osteodermos o por cráneos aislados respectivamente.

Expresiones materiales de las ocupaciones inkaicas y preinkaicas en los valles de San Antonio (sur de Jujuy) Peralta, Sebastian Matias; Cremonte, Maria Beatriz Las investigaciones realizadas en el Departamento San Antonio (sector centro meridional de la provincia de Jujuy) --área prácticamente desconocida en la arqueología de la provincia y del NOA-- están revelando una historia ocupacional dividida en dos capítulos diacrónicos: el referido a un poblamiento pre-inca y otro como resultado de la política de expansión estatal. Estas ocupaciones configuran dos tipos de Paisajes culturizados claramente diferenciados. El primero de ellos se manifiesta en un ambiente de Pre-puna, y se encuentra caracterizado por asentamientos de tipo aldeano semiconglomerados, que hasta el momento, si bien no contamos con fechados cronométricos, ubicamos temporalmente hacia finales del Período Agroalfarero Temprano (ca. 700 - 900 a. C.). Estas sociedades agrícolas con un patrón arquitectónico particular, parecen haberse extendido sobre las estribaciones orientales de la serranía del Chañi, desde el Norte del valle de Lerma (provincia de Salta) hasta las inmediaciones del área de Guerrero (provincia de Jujuy), siendo su configuración espacial desconocida hasta el momento en otros sectores de Jujuy y del NOA. El segundo tipo de manifestaciones culturales identificadas en el área de estudio corresponde a asentamientos que habrían integrado un sistema impuesto por el Estado incaico, dirigido al control político y económico durante un lapso muy breve y tardío (Cremonte et. al. 2002, 2003, 2005; Cremonte 2004).

A parameterization approach for Equation of State models: The case of Water-Hydrocarbon binary systems Ramello, Juan Ignacio; Rodriguez Reartes, Sabrina Belen; Cismondi Duarte, Martín; Zabaloy, Marcelo Santiago The water-hydrocarbon systems are highly asymmetric. The reproduction of their experimental fluid phase equilibria over wide ranges of conditions by models of the Equation of State (EOS) type is challenging. The EOS has to be flexible enough with respect to composition and temperature. On the other hand, special equilibrium information (such us binary critical points whose pressure is found to be locally maximum or minimum when looking at the critical line) may be hard to reproduce. This may be due more to the lack of a proper optimization strategy than to an intrinsic limitation of the model. A better optimization strategy can be obtained first by considering the equations that describe special phase equilibrium points. Another example of such points is a binary liquid-liquid-vapor equilibrium point where one of the liquid phases has, locally, a minimum or a maximum component mole fraction value. In this work we use, on one hand, the mathematical conditions of special phase equilibrium points. For deriving some of such conditions, we resort to the method of implicit derivation. On the other hand, we initialize the interaction parameters to be fitted by forcing the exact reproduction of some binary key coordinates of special phase equilibrium points. Next, we fit the parameters through a completely implicit approach, i.e., by setting up the optimization problem without using equality restrictions. In such a case, some experimentally unknown thermodynamic variables, e.g., a phase composition, become optimization variables together with the interaction parameters. Finally, if required, the level of implicitness of the optimization problem is gradually reduced as the estimates of the interaction parameter values become increasingly accurate. A fully explicit approach requires to repeatedly solve, during the optimization course, the systems of equations corresponding to conventional or special critical or phase equilibrium points. Thus, the explicit approach has a higher chance of presenting convergence problems than the semi-implicit or fully implicit approaches. In this work, we use an equation of state coupled to cubic mixing rules and temperature-dependent interaction parameters. This makes the model highly flexible and capable, in principle, of representing the phase behavior of water-hydrocarbon systems. For such systems, there is a considerable amount of information available in the literature regarding binary critical lines. We consider an important number of water-hydrocarbon binary systems. We evaluate the strengths and limitations of both, the modeling approach and the parameterization strategy.

Advancement on Bacterial Enzyme technology for industries: research and application of novel biocatalysts Cristobal, Hector Antonio; Abate, Carlos Mauricio; Cid, Alicia Graciela; Rajal, Verónica Beatriz A wide range of novel enzymes for biocatalysts adapted to industrial processes have been obtained from extremophile microorganisms. Marine environments possess an enormous microbial biodiversity and potential sources of many biological compounds for the development of exploitable biotechnology. The demand of biocatalysts adapted to extreme conditions (low or high temperatures, acidic or basic pH and high salt concentration) increases in the industry. The enzyme industry worldwide is valued at U$S 5.1 billion and it is predicted to show an annual increase in demand of 63%. Advances in biotechnology, coupled with growing scientific developments, promise technological innovations in a wide range of biotechnological applications for industries, which will be beyond estimation. Many fields of biotechnological studies need to understand the natural mechanisms in biological systems to use this information towards an integrated analysis of genes or proteins expression. In nature, as well as during industrial processes, bacteria are exposed to changes in environmental physico-chemical parameters, which may impair their growth or survival. In this chapter we focus the studies on Shewanella sp. G5, a psychrotolerant bacterium, which exhibits three β-glucosidases. Two of these isozymes were classified under the glycosyl hydrolase families 1 and 3, encoded by bgl-A (EF141823) and bgl (DQ136044) genes. These β-glucosidases may be of interest for winemaking and citrus juice technology processing at low temperatures. The identification of proteins or genes and its expression patterns under different growth conditions (carbon source, culture media and temperature) were studied by proteome analyses. Two-dimensional gel electrophoresis was performed and whole protein pattern of Shewanella sp. G5 revealed that 59 and 55 proteins spots were induced by cellobiose and glucose, respectively. Proteomic analyses showed that Shewanella sp. G5 re-organizes its metabolism in response to all the variables assayed, indicating expression of housekeeping and specific proteins for a particular condition. Determinate proteins spots expression showed increases, which allowed elucidating the quantitative changes relevant in the levels of genes expression. The identification of these proteins spots suggested that different master regulation schemes are involved in response to glucose and cellobiose carbon sources, and were compared with genome sequence data available for Shewanella oneidensis. These results allowed us to establish the optimum growth conditions for production of β-glucosidases, taking into account the greatest induction.

Stellar Structure and Evolution García Berro, Enrique; Althaus, Leandro Gabriel In this chapter the equations of stellar structure are introduced. Up-to-date descriptions of the most relevant microphysics needed to build reliable stellar configurations are also provided. These include the equation of state, nuclear reactions, opacities, and other less frequently discussed physical processes, such as diffusion and radiative levitation. The necessary numerical techniques currently employed to build evolutionary stellar models as well as the otherwise necessary boundary conditions needed to integrate the equations of stellar structure are also addressed. Finally, an overview of the current state-of-the-art modeling is given.

Aetosauria: a clade of armoured pseudosuchians from the Upper Triassic continental beds Desojo, Julia Brenda; Heckert, Andrew B.; Martz, Jeffrey W.; Parker, William G.; Schoch, Rainer; Small, Bryan J.; Sulej, Tomasz Aetosauria is a clade of obligately quadrupedal, heavily armoured pseudosuchians known from Upper Triassic (late Carnian?Rhaetian) strata on every modern continent except Australia and Antarctica. As many as 22 genera and 26 species ranging from 1 to 6 m in length, and with a body mass ranging from less than 10 to more than 500 kg, are known. Aetosauroides scagliai was recently recovered as the most basal aetosaur, placed outside of Stagonolepididae (the last common ancestor of Desmatosuchus and Aetosaurus). Interrelationships among the basal aetosaurs are not well understood but two clades with relatively apomorphic armour ? the spinose Desmatosuchinae and the generally wide-bodied Typothoracisinae ? are consistently recognized. Paramedian and lateral osteoderms are often distinctive at the generic level but variation within the carapace is not well understood in many taxa, warranting caution in assigning isolated osteoderms to specific taxa. The aetosaur skull and dentition varies across taxa, and there is increasing evidence that at least some aetosaurs relied on invertebrates and/or small vertebrates as a food source. Histological evidence indicates that, after an initial period of rapid growth, lines of arrested growth (LAGs) are common and later growth was relatively slow. The common and widespread Late Triassic ichnogenus Brachychirotherium probably represents the track of an aetosaur.

Recent studies on alginate blends, composites, and nanocomposites Lencina, María Malvina Soledad; Andreucetti, Noemi Amalia; Gomez, Cesar Gerardo; Villar, Marcelo Armando Alginate is the generic name given to the salts of alginic acids. Alginic acids are polysaccharides molecules which are built up of uronic acid residues, molecules with a carboxyl group on the carbon that is not part of the ring, Commercial alginates are currently obtained by extraction from brown seaweeds such as Laminaria digitata, Laminaria hyperborea, and Macrocystis pyrifera. However, several bacteria such as the nitrogen-fixing aerobe Azotobacter vinelandii and the opportunistic pathogen Pseudomonas aeruginosa also produce alginate. Alginates are unique in terms of their properties such as emulsifiers, thickeners, stabilizers, gelling and film forming, resultingin several applications for the food and pharmaceutical industries. Alginate has been regarded as an excellent polysachaccharide for gel systems because of its unique features such as biocompatibility, biodegradability, immnogenecity, and non-toxicity. In the biomedical area, alginates have been used as devices in several human health applications, such as excipients in drug delivery (DDS), wound dressings, as dental impression materials and in some formulations preventing gastric reflux, among others. Main characteristics and chemical modification, along with some interesting properties and applications are reviewed in this chapter.

Myths and Facts on cytosolic sucrose hydrolysis Vargas, Walter Alberto; Martin, Mariana Laura; Salerno, Graciela Lidia Sucrose plays an essential role in nature as part of the carbon dioxide assimilation pathway in the biosphere. Particularly, in plants occupies a unique position being essential for the allocation of carbon resources for growth and respiration, and participates in a regulatory network that coordinates metabolism and development. Its metabolism is strictly coordinated with photosynthesis-related genes by a feed-back regulation and a sugar signaling pathway. Also, sucrose accumulation has been shown to be involved in environmental stress responses and its degradation has been associated with a high demand of carbon and energy in sink tissues and anoxic environments. In the last decades, several studies on sucrose degradation in plant cells brought to light novel trails on carbon trafficking and the metabolic paths leading to regulation of gene expression and metabolic adjustment. However, recent findings point to an intricate relationship between sucrose metabolism and the whole plant physiology. This review is focused on the elusive Alkaline/Neutral-Invertase (A/N-Inv) isoforms, which have been long believed as cytosol-exclusive enzymes that hydrolyze the disaccharide for general or maintenance functions in the plant cell. Nevertheless, the story has changed in last few years when novel subcellular localizations and essential functions for a number of key physiological processes were demonstrated for A/N-Invs. From being minor proteins, scarcely mentioned in comprehensive descriptions of carbon flux in plants, these enzymes became leading actors in sucrose metabolism with significant roles in root morphogenesis, photosynthetic apparatus biosynthesis, and abiotic stress adaptation. The aim of this review article is to present a detailed and updated discussion of the most significant findings on the physiological properties of A/N-Invs. Also, we incorporate this group of invertases in the metabolic paths leading sucrose into the different circuits that govern carbon partitioning, storage and regulation of the molecular biology of the plant cell.

Cien Años de música argentina: Desde 1910 a nuestros días Pujol, Sergio Alejandro Cien años de música argentina es un mapa que contiene tanto los sitios "clásicos" como los "populares", indicando también las rutas que conectan unos con otros. Esta dicotomía tuvo una importancia decisiva en la historia cultural de Occidente, al menos hasta la década de los años 60.La Argentina, por las características de su historia social, ha sido un escenario privilegiado de permeabilidad entre escritura y oralidad musicales pero aun así las tensiones que atravesaron el mundo de la cultura a lo largo de la primera mitad del siglo XX reforzaron la polarización entre música clásica y música popular. Este libro da cuenta de esa polaridad, a la vez que se propone presentar un panorama integrado de la producción musical argentina entre 1910 y nuestros días.

Effect of entomopathogenic nematodes on the plant-parasitic nematode Nacobbus aberrans Caccia, Milena Guadalupe; Lax, Paola; Doucet, Marcelo Edmundo Nacobbus aberrans is a sedentary endoparasite nematode that forms galls in the roots of infected plants and produces important economic losses in some countries of the American continent. It has a wide host range, attacking mainly potato, tomato, sugar beet, and pepper crops. A reduction in the plant-parasitic nematode populations in the presence of entomopathogenic nematodes (EPNs) has been frequently reported. In the present work, the effect of the application of two native EPN isolates (Steinernema rarum and Heterorhabditis bacteriophora) on a N. aberrans population was evaluated in tomato plants under greenhouse conditions. Sixty days after inoculation, the number of galls and egg masses and the reproduction factor (RF) of N. aberrans were calculated. Of the variables analyzed, only the RF was significantly lower in both EPN treatments than in control. N. aberrans reproduction decreased by 57 and 53 % in plants inoculated with S. rarum and H. bacteriophora, respectively. These results showed that EPNs and their bacterial symbionts affected the reproductive potential of the N. aberrans population. This is the first study addressing the use of EPNs in the control of this important plant-parasitic nematode. © 2012 Springer-Verlag.

A novel method to produce a hierarchical porous carbon as a conductive support of PtRu particles. Effect on CO and Methanol electrooxidation Baena Moncada, Angelica Maria; Planes, Gabriel Angel; Moreno, Mario Sergio Jesus; Barbero, César Alfredo The fabrication and catalytic properties of hierarchical porous carbon loaded with PtRu particles was studied. A silica nanoparticles opal is filled with resorcinol/formaldehyde resin, which is then pyrolized to form a macroporous carbon. Depending on synthesis conditions the volume contraction induces mesopore formation in the macroporous carbon, creating a hierarchical porous carbon (HPC). The material consists of a thick, highly porous electrocatalytic film. PtRu nanoparticles were loaded inside the HPC by reduction of metallic ions with formic acid. The electrocatalytic activity toward CO and methanol oxidation was evaluated. The current densities for methanol electrooxidation at 60 °C (220 μA cm -2 and 120 Ag -1 at 0.55 V RHE) reveals high activity, suggesting that the catalysts consist of well disperse, small PtRu nanoparticles, with a low degree of agglomeration and good accessibility for reactants.

Computabilidad, complejidad computacional y verificación de programas Rosenfeld, Ricardo; Irazábal, Jerónimo Computabilidad, Complejidad Computacional y Verificación de Programas contiene lasquince clases que conforman la asignatura Teoría de la Computación y Verificación deProgramas, una introducción a la teoría de la computabilidad y complejidadcomputacional de problemas y la teoría de correctitud de programa. El libro es una suerte de segunda edición reducida deTeoría de la Computación y Verificación de Programas, de los mismos autores, editadoen 2010 por la EDULP conjuntamente con McGraw-Hill, el cual incluye además de lasclases de la asignatura básica, las de Teoría de la Computación y Verificación deProgramas Avanzada.El nuevo trabajo excluye principalmente la complejidad espacial, la verificaciónde los programas no determinísticos y concurrentes, el empleo de la lógica temporalpara verificar los programas reactivos, y la semántica denotacional de los lenguajes deprogramación, tópicos tratados en la obra anterior. De todos modos, en la presentepublicación hay secciones, breves, dedicadas a la jerarquía espacial, la terminación conhipótesis de fairnes de los programas no determinísticos, y la verificación de losprogramas concurrentes con memoria compartida, desarrolladas de la manera en quedichos temas son referenciados en la asignatura básica.

Prolactinomas: Role of VEGF, FGF-2 and CD31 Inés, María; Pérez Millán, M. I.; Cristina, Carolina; Berner, Silvia Ines; Becu, Damasia Pituitary tumors rarely produce metastasis, but cause considerable morbidity and mortality. Each pituitary tumor of clonal origin represents the multifactorial result of failure of different regulatory events where growth and angiogenic factors may play critical roles in hormone secretion and cell proliferation. Prolactinomas, pituitary tumors which secrete prolactin, are generally treated successfully with dopamine agonists, even though a 10–15 % are resistant to this pharmacological therapy. The role of angiogenesis in pituitary tumor development has been questioned, as pituitary tumors have been usually found to be less vascularized than the normal pituitary tissue. Nevertheless, a significantly higher degree of vasculature has been shown in invasive pituitary prolactinomas when compared to noninvasive prolactinomas. Furthermore, it has also been described that macroprolactinomas are more vascular than microprolactinomas. Many growth factors and their receptors are involved in pituitary tumor development. For example, VEGF, FGF-2, FGFR1 and PTTG, which give a particular vascular phenotype, are modified in pituitary adenomas. Inhibitors of angiogenesis, Thrombospondin-1 and FGF-2 endogenous antisense have also been detected. In particular, vascular endothelial growth factor (VEGF) the central mediator of angiogenesis in endocrine glands, was encountered in experimental and human pituitary tumors at different levels of expression, and in particular, in dopamine resistant prolactinomas. Even though the role of angiogenesis in pituitary adenomas is contentious, VEGF, making permeable pituitary endothelia, might contribute to adequate temporal vascular supply and mechanisms other than endothelial cell proliferation. The study of angiogenic factor expression in aggressive prolactinomas with resistance to dopamine agonists will yield important data in the search of therapeutical alternatives.

Bioactividad de beta-galactosidasa en un ambiente que simula la superpoblación molecular de los alimentos y del quimo. Ledesma, Darío; Perillo, Maria Angelica; Nolan, María Verónica El objetivo del presente trabajo fue investigar el efecto de la superpoblación macromolecular (SPM) sobre la cinética de hidrólisis de o-nitrofenil galactopiranósido (ONPG) catalizada por β -galactosidasa de E.coli (β -Gal). Para esto se aplicaron dos técnicas, espectroscopia UV-Visible (EF) y Calorimetría de titulación isotérmica (ITC), las cuales están basadas en principios físicos diferentes. La condición de SPM se simuló con disoluciones de polietilenglicol PM 6000 (PEG6000) a distintas concentraciones (0 a 35 % P/V). Los resultados arrojados por ambas técnicas (EF e ITC) no mostraron diferencias significativas, permitiéndonos: a) validar el uso del ITC para estudios cinéticos de reacciones catalizadas por enzimas en condiciones de SPM y b) aceptar que la SPM no interfirió sobre el comportamiento espectroscópico del producto de la reacción estudiada. El principal hallazgo fue que la velocidad de reacción (Vmax) no se vio afectada, mientras que la afinidad de la enzima por su sustrato (KM) sufrió una disminución significativa (KM aumentó de 0,14 a 1 mM para 0 y 35 % P/V PEG6000, respectivamente) a medida que aumentó la concentración del agente superpoblante. Esta disminución en la afinidad a altas concentración de PEG6000 podría deberse a la restricción difusional que impone la alta densidad molecular presente en estas condiciones. Este resultado es importante para el diseño de sistemas terapéuticos de sustitución enzimática.

Comunidad impropia: Estéticas posmodernas del lazo social Dipaola, Esteban Marcos En el libro se describe y analiza desde la literatura reciente en el campo, las transformaciones en el orden social, cultural y económico del capitalismo y sus incidencias en las formas de interacción social, tomando en cuenta los vínculos, la normatividad y como se producen actualmente las comunidades e identidades. Desde ese lugar, se entiende y piensa la posmodernidad y la globalización y las dimensiones desde las cuales comprender los efectos estéticos que sobre el lazo social producen las nuevas dinámicas de relaciones entre individuos.