Iterative design of dynamic experiments in modeling for optimization of innovative bioprocesses
Cristaldi, Mariano Daniel; Grau, Ricardo José Antonio; Martínez, Ernesto Carlos
Finding optimal operating conditions fast with a scarce budget of experimental runs is a key problem to speed up the development and scaling up of innovative bioprocesses. In this paper, a novel iterative methodology for the model-based design of dynamic experiments in modeling for optimization is developed and successfully applied to the optimization of a fed-batch bioreactor related to the production of r-interleukin-11 (rIL-11) whose DNA sequence has been cloned in an Escherichia coli strain. At each iteration, the proposed methodology resorts to a library of tendency models to increasingly bias bioreactor operating conditions towards an optimum. By selecting the ‘most informative’ tendency model in the sequel, the next dynamic experiment is defined by re-optimizing the input policy and calculating optimal sampling times. Model selection is based on minimizing an error measure which distinguishes between parametric and structural uncertainty to selectively bias data gathering towards improved operating conditions. The parametric uncertainty of tendency models is iteratively reduced using Global Sensitivity Analysis (GSA) to pinpoint which parameters are keys for estimating the objective function. Results obtained after just a few iterations are very promising.
La resistencia de la agricultura familiar tradicional en el Chaco, Argentina; The resistance of traditional family agriculture in El Chaco, Argentina
Valenzuela, Cristina Ofelia; Scavo, Ángel Vito
En este artículo se analiza la resistencia de los esquemas agrícolas tradicionales de tipo familiar a las transformaciones implícitas en la evolución tecnológica y los nuevos modelos de organización de la producción agrícola. Esta resistencia se analiza en sus manifestaciones individuales y colectivas y en su propósito de rescate y permanencia de una identidad productiva, construida en torno a prácticas y agentes específicos en una provincia periférica argentina.; This article analyses the resistance of traditional family agricultural schemes to the implicit transformations of technological evolution and new organisation models of agricultural production. This resistance is analysed in its individual and collective manifestations, as well as from the point of view of its purposes of rescue and permanence of a productivity identity, built upon practices and specific agents in a peripheral province of Argentina.
Caracterización de cúmulos abiertos a través de correlaciones cruzadas con librerías de espectros
Maia, F. F. S.; Santos Jr, Joâo F. C.; Corradi, W. J. B.; Piatti, Andres Eduardo
We present a characterization method based on spectral cross-correlation to obtain the physical parameters of the controversial stellar aggregate ESO 442-SC04. The data used was obtained with GMOS at Gemini-South telescope. Spectral types, effective temperature, suface gravity and metallicities parameters were determined using FXCOR to correlate cluster spectra with ELODIE spectral library and selecting the best correlation matches using the Tonry and Davis Ratio (TDR). Analysis
of the results suggests that the stars in ESO 442-SC04 are not bound and therefore they do not constitute a physical system.; En este trabajo presentamos un m´etodo de caracterizacion basado en la correlacion cruzada de espectros de estrellas en el controvertido objeto ESO 442-SC04. Utilizamos espectros obtenidos con el multiespectrografo GMOS del telescopio Gemini Sur. Determinamos tipos espectrales, velocidades radiales, temperaturas efectivas y gravedades superficiales empleando la tarea FXCOR de IRAF, para correlacionar los espectros estelares observados con los de la librerıa ELODIE, en combinacion con la razon Tonry-Davis para seleccionar el mejor ajuste. Un analisis de los resultados sugiere que las estrellas observadas en ESO 442- SC04 no constituyen un sistema fısico.
Partitioning of Carboxylic Acid Between Oil and Water Phases: Experimental, Correlation, and Prediction
Campanella, Alejandrina; Mandagaran, Beatriz Adriana; Campanella, Enrique Angel
Partition coefficients for the carboxylic acids (A) acetic and formic acids between oil and water were measured, correlated, and predicted. The experiments were conducted by equilibrating the systems, soybean oil (SO)– H2O–A and fatty acid methyl ester (FAME)–H2O–A, at 40 ºC employing different compositions. The partition coefficients were correlated using the UNIQUAC model and, also, predicted by calculating the activity coefficients of the carboxylic acid in the two phases using a group contribution method, the UNIFAC equation. Agreement of experimental partition coefficients values with those estimated by UNIFAC are fair. Other experimental data from literature were also correlated and are discussed.
A comparative analysis of the temperature behavior and multiple tropopause events derived from GPS, radiosonde and reanalysis datasets over Argentina, as an example of Southern mid latitudes
Lakkis, Susan Gabriela; Canziani, Pablo Osvaldo
Investigaciones recientes sobre climatología de la estructura térmica y parámetros de tropopausa en los trópicos, basadas en radiosondas, datos de satélite y productos de reanálisis, muestran una buena concordancia entre los radiosondeos (RS) y los datos derivados de ocultaciones, como las radio ocultaciones del GPS (GPS RO), y los reanálisis. Sin embargo, en la región meridional extratropical, especialmente en latitudes medias y altas, a menudo hay considerables diferencias en los perfiles de temperatura al ir aumentando la latitud, dependiendo de la variabilidad de la altura y evolución de la tropopausa. El propósito del presente trabajo es mostrar el comportamiento de los perfiles de temperatura obtenidos de las ocultaciones GPS y los perfiles diarios y mensuales de reanálisis derivados del ERA 40 comparados con los valores de radiosondeo para eventos detectados en Argentina, como ejemplo de latitudes entre 30◦ y 60◦ sur, durante el período 2001-2002. Por otro lado, el estudio analiza también parámetros como la temperatura, altura y presión de los niveles significativos de radiosondeo y de las ocultaciones con el fin de analizar la existencia de eventos con simple y múltiple tropopausa. Los resultados obtenidos de la comparación entre las diferentes bases de datos muestran que en la mayoría de los casos las ocultaciones proveen perfiles de temperatura semejantes a aquellos graficados a partir de datos de radiosondeo, en contraposición a los obtenidos a partir de los productos de reanálisis, tanto diarios como mensuales. No obstante es posible observar que las diferencias entre las RO y los RS son más notorias para alturas superiores a los niveles de tropopausa, mientras que decrecen en la troposfera. Relacionado con los eventos de múltiple tropopausa, el análisis realizado muestra que los valores de temperatura y altura de la tropopausa de las RS y las RO son semejantes cuando sólo es considerada la LRT1, con diferencias crecientes a medida que las estaciones analizadas están ubicadas en latitudes más altas. A pesar de esta concordancia para la LRT1, los resultados muestran que solo los datos procedentes de radiosondeos son capaces de detectar eventos con LRT2 y LRT3.; Recent research on climatologies for temperature structure and tropopause parameters in the tropics, based on radiosonde, satellites data and model reanalysis show good agreement between radiosonde (RS) and data derived from remote sounding, such as GPS Radio Occultation (GPS RO), and reanalysis. The agreement is remarkably good over and immediately near the tropics. However, in the southern extra tropical region, especially at medium and high latitudes, there are often considerable differences in the temperature profiles as latitudes increases, which depends on the variability of location and evolution of the tropopause. The purpose of this work is to compare the behaviour of temperature profiles derived from GPS RO, daily and monthly ERA 40 reanalysis means and nearby radiosonde measurements in the southern extra tropical region. Argentina serves as an example of latitudes between 30◦ - 60◦S. The data covers 2001-2002 and analyses parameters such as temperature, pressure, and height derived rom radiosonde and satellite data in order to detect single and multiple tropopause events. The results show that in most cases are GPS RO more closely related to RS measurements than to reanalysis profiles, both for daily values, monthly means and their standard deviations. However, GPS RO deviations increase with respect to RS for heights above the tropopause, i.e., in the stratosphere, and decrease into the troposphere. Radiosonde and GPS appear to be in good agreement for tropopause temperatures and heights estimates when a single tropopause (LRT1) is considered, but with decreasing agreement as latitudes increase. Furthermore, while single and double tropopause events can be detected in RS observations this is less common for the GPS RO retrievals.
10 ausentes del Patrimonio: El Patrimonio demolido. Imaginar otra Buenos Aires a través de las fotografías
Gutiérrez, Ramón; Mendez, Patricia Susana
El texto resulta un análisis de diversos objetos arquitectónicos de valor en el contexto urbano porteño ya desaparecidos y que se rescatan a través de la fotografía. La idea fue el producir una toma de conciencia sobre el valor de la arquitectura a nivel patrimonial y también del valor de la fotografía como documento acabado de la historia arquitectónica y urbana.
The multimeric structure of polycystin-2 (TRPP2): Structural - Functional correlates of homo- and hetero-multimers with TRPC1
Zhang, Peng; Luo, Ying; Chasan, Bernard; González Perrett, Silvia; Montalbetti, Nicolas; Timpanaro, Gustavo A.; Cantero, Maria del Rocio; Ramos, Arnolt J.; Goldmann, Wolfgang H.; Zhou, Jing; Cantiello, Horacio Fabio
Polycystin-2 (PC2, TRPP2), the gene product of PKD2, whose mutations cause autosomal dominant polycystic kidney disease (ADPKD), belongs to the superfamily of TRP channels. PC2 is a non-selective cation channel, with multiple subconductance states. In this report, we explored structural and functional properties of PC2 and whether the conductance substates represent monomeric contributions to the channel complex. A kinetic analysis of spontaneous channel currents of PC2 showed that four intrinsic, non-stochastic subconductance states, which followed a staircase behavior, were both pH- and voltage-dependent. To confirm the oligomeric contributions to PC2 channel function, heteromeric PC2/TRPC1 channel complexes were also functionally assessed by single channel current analysis. Low pH inhibited the PC2 currents in PC2 homomeric complexes, but failed to affect PC2 currents in PC2/TRPC1 heteromeric complexes. Amiloride, in contrast, abolished PC2 currents in both the homomeric PC2 complexes and the heteromeric PC2/TRPC1 complexes, thus PC2/TRPC1 complexes have distinct functional properties from the homomeric complexes. The topological features of the homomeric PC2-, TRPC1- and heteromeric PC2/TRPC1 channel complexes, assessed by atomic force microscopy, were consistent with structural tetramers. TRPC1 homomeric channels had different average diameter and protruding height when compared with the PC2 homomers. The contribution of individual monomers to the PC2/TRPC1 hetero-complexes was easily distinguishable. The data support tetrameric models of both the PC2 and TRPC1 channels, where the overall conductance of a particular channel will depend on the contribution of the various functional monomers in the complex.
Palynological record of the Paleogene Río Leona Formation (southernmost South America): Stratigraphical and paleoenvironmental implications
Barreda, Viviana Dora; Palazzesi, Luis; Marenssi, Sergio Alfredo
Terrestrial palynomorph assemblages have been recovered from the Río Leona Formation, southwestern Santa Cruz Province, southern South America. Organic debris (spores, pollen grains, fresh water algae, plant tissues and fungi) are preserved in shales associated with other plant fossil remains (leaves and wood). The Río Leona Formation is here assigned to the early Late Oligocene based on the presence of key species of the M–M palynological zone (Margocolporites tenuireticulatus Barreda, Diporites aspis Pocknall and Mildenhall, Granodiporites nebulosus Partridge, Mutisiapollis spp.) and the virtual absence of warmth-adapted taxa (abundant from the latest Late Oligocene to Middle Miocene in Patagonia). A temporal gap between the Río Leona Formation and the overlying Centinela Formation (Early Miocene) – exposed in the studied region – is suggested here based on the differences observed in their palynological assemblages. The Río Leona Formation was deposited in a continental environment, with local peat swamps and coastal plain environments. The presence of Antarctic lineages in the lower and middle sections of the Río Leona Formation is consistent with the cooling trend globally recognized during the Late Eocene and Early Oligocene times. The appearance of some Neotropical families in the upper section might indicate the beginning of the Late Oligocene warming event. Records of Asteraceae (Mutisiapollis telleriae Barreda and Palazzesi sp. nov.), Menyanthaceae (Striasyncolpites laxus Mildenhall and Pocknall), and Rosaceae (Psilatricolporites quenua Barreda and Palazzesi sp. nov., Psilatricolporites sp.) are the oldest reports in Patagonia to date, and provide significant information on the early divergence and radiation times of these major angiosperm families.
Adiciones al conocimiento de Astrapothericulus (Mammalia, Astrapotheria): anatomía cráneo-dentaria, diversidad y distribución; Additions to the knowledge of Astrapothericulus (Mammalia, Astrapotheria): craniodental anatomy, diversity and distribution
Kramarz, Alejandro Gustavo
Astrapothericulus Ameghino es el taxón que tipifica las “capas Astrapothericulenses” (Mioceno temprano, Patagonia central). Aunque hasta ahora pobremente conocido, se lo distinguía de otros astrapoterios oligo-miocénicos por su tamaño comparativamente pequeño y por presentar rasgos mandibulares y dentarios menos especializados. Se redescribe y compara aquí la dentadura en base a nuevos y abundantes materiales y se describe el primer resto craneano referible indudablemente a la especie genotípica Astrapothericulus iheringi. Los molariformes se caracterizan por ser de corona más baja que en Astrapotherium magnum (Santacrucense) y con cíngulos basales mucho más gruesos y prominentes, y fléxido labial del p4 ausente o muy superficial, como en Parastrapotherium (Deseadense-Colhuehuapense). Los caninos pueden ser pequeños y radiculados a grandes defensas de base abierta, que aquí se interpreta como variaciones dimórficas. El cráneo y la mandíbula presentan rasgos aparentemente primitivos respecto de Astrapotherium y ParAstrapotherium (e.g. nasales menos retraídos, órbitas más grandes, mandíbula con diastema más corto, sínfisis más estrecha y cóncava). Sin embargo, análisis filogenéticos recientes concluyen que éstas serían reversiones autapomórficas. Astrapothericulus se habría diferenciado a partir de un ancestro de talla mucho mayor estructuralmente próximo a Astrapotherium, y los caracteres mencionados, posiblemente paedomórficos, estarían asociados a la posterior reducción del tamaño corporal como resultado de procesos heterocrónicos. De las especies descriptas, aquí solamente se interpretan como válidas Astrapothericulus iheringi (=Astrapothericulus hebetatum) y Astrapothericulus emarginatus Ameghino (=Astrapothericulus peninsulatus). El género se registra también en capas de edad Colhuehuapense y en los niveles superiores de la Formación Pinturas con fauna típicamente Santacrucense, por lo que su distribución excede cronológicamente las capas portadoras de “fauna Astrapothericulense”.; Astrapothericulus Ameghino is the taxon which typifies the Astrapothericulan beds (Early Miocene, central Patagonia). Although so far it is poorly known, it was distinguished from other Oligo-Miocene astrapotheres by its comparatively smaller size and by having less specialized mandibular and dental features. The dentition is herein redescribed and compared based on new and abundant materials, and the first cranial remain positively referred to the genotypic species Astrapothericulus iheringi is described. The cheek teeth are lower crowned than in Astrapotherium magnum (Santacrucian), the basal cingula are broader and more prominent, and the p4 hypoflexid is absent or very superficial, as in Parastrapotherium (Deseadan-Colhuehuapian). The canines can be small and rooted or large rootless tusks, which is herein interpreted as dimorphic variations. The skull and jaw exhibit supposedly primitive characters in relation to Astrapotherium and Parastrapotherium (e.g. less retracted nasals, larger anterior orbits, mandible with shorter, narrower and more concave symphysis). However, recent phylogenetic analyses concluded that these are autapomorphic reversions. Astrapothericulus would have differentiated from an ancestor with much larger size, structurally close to Astrapotherium, and the mentioned characters, presumably paedomorphic, would be associated to a secondary reduction of body size as a result of a heterochronic processes. Of the described species, only Astrapothericulusiheringi (=Astrapothericulus hebetatum) and Astrapothericulus emarginatus Ameghino (=Astrapothericulus peninsulatus) are herein interpreted as valid. The genus also occurs in levels of Colhuehuapian age and in the upper levels of the Pinturas Formation bearing typical Santacrucian fauna, and consequently its distribution exceeds chronologically “Astrapothericulan fauna” bearing beds.
Análisis de citación y de redes sociales para el estudio del uso de revistas en centros de investigación. Un aporte al desarrollo de colecciones; Análise de citação e redes sociais para o estudo do uso de revistas nos centros de pesquisa. Uma abordagem ao desenvolvimento de acervos; Analysis of citation and social nets for the study of the use of journals in the research centers. An approach to the development of collections
Gonzalez, Claudia Marcela
Se presenta en este trabajo una aproximación metodológica al estudio de uso de revistas por parte de investigadores. Integrando la técnica de Análisis de Citaciones (AC) y de Análisis de Redes Sociales (ARS) se elaboran mapas bibliométricos que aportan capacidad de síntesis de información compleja. Se estima que su utilización en la evaluación de colecciones aportaría información valiosa para la distribución equitativa de los recursos económicos destinados a la compra de títulos, y para la optimización de su disponibilidad y acceso.; O objetivo deste artigo é o de apresentar uma abordagem metodológica ao estudo do uso de revistas por parte dos pesquisadores. Além da técnica de Análise de Citação e de Análise de Redes Sociais, são elaborados mapas bibliométricos que proporcionam capacidade de síntese de uma informação complexa. Sua utilização na avaliação dos acervos traria valiosa informação para a distribuição eqüitativa dos recursos econômicos destinados à compra de novos títulos e otimização de sua disponibilidade e acesso.; The objective of this article is to present a methodological approach to the study of use of journals by researchers. In addition to the technique of Analysis of Citation and Analysis of Social Nets, bibliometrical maps are elaborated which proportionate capacity of synthesis of complex information. Their utilization in evaluating collections would bring in valuable information for the equitatifve distribution of the economic resources alloted to the purchase of tittles and optimization of their availability and access.
Los intelectuales apristas y la cultura popular: Un acercamiento a las reflexiones de Luis Alberto Sánchez y Víctor Raúl Haya de la Torre sobre el indigenismo
Sessa, Leandro
En el período de "entreguerras", la ruptura con el positivismo por parte de numerosos pensadores produjo la emergencia de discursos relegitimadores de los sectores populares en todo el continente. Este artículo aborda desde una perspectiva de análisis del discurso el pensamiento de dos intelectuales identificados con el aprismo (Víctor Raúl Haya de la Torre y Luis Alberto Sánchez) acerca del problema del indigenismo. En este sentido, se intentan señalar continuidades y rupturas con otras corrientes indigenistas y analizar las estrategias discursivas presentes en los escritos apristas, cuyas particularidades están dadas por los intentos de construcción un partido político nacional / continental.; During the World inter-wars period, the break of Positivism on the part of many thinkers produced an emergence of discourses re-legitimizing popular sectors across the conti-nent. From a discourse analysis perspective, this article approaches the thought of: Luis Alberto Sánchez and Víctor Raúl Haya de la Torre on the problem of Indigenism. Both in-tellectuals are identified with the Aprista mo-vement. First, the article points continuities and breaks Aprismo might have had in com-mon with other indigenous currents of thought and, second; it analyzes the discursive strategies of aprista’s writings. The particularities of these writings are given by the APRA’s attempt to build a national and continental political party.
Genetic and Morphometric Variability in Caiman latirostris (Broad-Snouted Caiman), Reptilia, Alligatoridae
Amavet, Patricia Susana; Vilardi, Juan Cesar; Rosso, Esteban; Saidman, Beatriz Ofelia
Caiman latirostris (broad-snouted caiman) is a crocodilian species from Argentina subject of management plans. The goal of this study was estimating the distribution of genetic variability using RAPD markers and quantitative traits in wild populations of C. latirostris from Santa Fe province, Argentina. We sampled animals from four populations to obtain DNA and morphometric measurements. Eight RAPD primers were used and PCR products were analyzed on 4% polyacrylamide gels stained with silver nitrate. Eleven allometric measurements were obtained in animals within 48 hr after birth. We were able to reveal a relatively high number of variable markers in the studied populations. Our estimates of polymorphism and heterozygosity are higher than recorded values in other crocodilians using isozymes, the studied populations showed low levels of gene flow and some population subdivision. The study of quantitative traits conducted by nested analysis of variance and principal component analysis indicated higher levels of variance among nests within populations than among populations. We found that some head measurements have the highest contribution to morphological differences among populations; this fact could support the role of these traits in reproductive or feeding behavior. Estimated genetic differentiation value (FST) among populations was higher than quantitative trait differentiation value (QST), suggesting a higher contribution of neutral than adaptive loci to the genetic differentiation among populations. Quantitative traits are probably more related with fitness and the differentiation among populations remained relatively lower. The high heritability estimated for some traits indicates great potential to improve them in management plans.
On Darwin's footsteps across the Andes: Tithonian-Neocomian fossil invertebrates from the Piuquenes pass; Tras las huellas de Darwin a través de los Andes: invertebrados fósiles del Tithoniano Neocomiano del paso de Piuquenes
Aguirre-Urreta, Maria Beatriz; Vennari, Verónica Vanesa
El objetivo de este trabajo es presentar una breve revisión moderna de la geología del Paso de Piuquenes en los Andes Principales de Chile y Argentina y describir una pequeña fauna de invertebrados del Tithoniano-Neocomiano compuesta principalmente por amonites. Se compara también el conocimiento de esta región con la referida por Darwin en su famoso libro sobre la geología de América del Sur.; The aim of this work is to summarize the modern knowledge of the geology of the Piuquenes Pass, in the Main Andes of Argentina and Chile, and to describe a small fauna of Tithonian-Neocomian invertebrates mostly represented by ammonites. The present knowledge of the region is compared with Darwin´s, as expressed in his famous book on the Geology of South America.
Entre el sujeto y la estructura: Relectura de una polémica clásica sobre el Estado capitalista; Between subject and structure: A rereading of a classic polemic on the capitalist State
Duhalde, Santiago
En este trabajo realizo una comparación de algunos de los principales ítems que tocan Ralph Miliband y Nicos Poulantzas en su famosa discusión de la década de 1970. De esta manera, concluyo que las divergencias teóricas y metodológicas que allí se presentan se deben principalmente a diferencias ontológicas y epistemológicas, yendo, así, un poco más allá del lugar donde se había circunscrito históricamente el análisis del debate, que era el de la contraposición entre un punto de vista estructuralista y otro instrumentalista sobre el Estado capitalista. Finalmente, termino con una conclusión que llama a retomar este debate pero con nuevas herramientas que permitan poner en tela de juicio los principios modernos que rigen la discusión sobre la determinación del sujeto o la estructura en los fenómenos de la realidad social.; This article examines some of the principal themes in the debate between Ralph Miliband and Nicos Poulantzas in the 1970s. I argue that their theoretical and methodological conflicts were principally a product of ontological and epistemological differences. This analysis goes beyond the usual commentaries on their debate, which tend to see it as an argument between a structuralist and instrumentalist view of the capitalist State. Finally, I end with a call to renew the debate, but now with new tools. We need to question those modern principles that govern the discussion of how the subject, or the structure of social reality, is determined.
A multiperiod model for production planning and design in a multiproduct batch environment
Moreno, Marta Susana; Montagna, Jorge Marcelo
A general multiperiod model to optimize simultaneously production planning and design decisions applied to multiproduct batch plants is proposed. This model includes deterministic seasonal variations of costs, prices, demands and supplies. The overall problem is formulated as a mixed-integer linear programming model by applying appropriate linearizations of non-linear terms. The performance criterion is to maximize the net present value of the profit, which comprises sales, investment, inventories, waste disposal and resources costs, and a penalty term accounting for late deliveries. A noteworthy feature of this approach is the selection of unit dimensions from the available discrete sizes, following the usual procurement policy in this area. The model simultaneously calculates the plant structure (parallel units in every stage, and allocation of intermediate storage tanks), and unit sizes, as well as the production planning decisions in each period (stocks of both product and raw materials, production plans, policies of sales and procurement, etc.).
Cambios ambientales y arqueología en el actual territorio del Uruguay
Bracco Boksar, Roberto; del Puerto, Laura; Castiñeira Latorre, Carola; Garcia Rodriguez, Felipe; Panario, Daniel; Inda, Hugo
Los cambios ambientales han ocupado un lugar central en la arqueología del Uruguay a partir de las investigaciones desarrolladas en la cuenca de la Laguna Merín, induciendo desarrollos técnico-metodológicos específicos. Este trabajo expone los resultados alcanzados a partir de los registros obtenidos de testigos de fondos de lagunas, particularmente el registro silicofitolítico. Los índices de humedad y temperatura se obtuvieron a partir de la relación de células chloridoides con el total de células cortas de gramíneas C4 y considerando las fluctuaciones de los fitolitos pooides. Los fitolitos chloridoides se producen en gramíneas C4, predominantes en regiones cálidas, áridas a semiáridas o con marcada estacionalidad en las precipitaciones. Las fluctuaciones de los fitolitos pooides, producidas por gramíneas C3, predominantes en zonas frías de altas latitudes y/o altitud, responden como indicadores de temperatura. En consecuencia una mayor representación relativa de fitolitos chloridoides indica una mayor aridez. Una mayor representación de fitolitos pooides señala una menor temperatura. A partir de testigos lagunares, con ambos indicadores se reconocieron tres períodos climáticos para el lapso 7,0-0,5 ka 14C AP. Por último se señalan interpretaciones que han relacionado estos períodos con cambios culturales, al igual que otras correlaciones que pueden ser relevantes al momento de interpretar o explicar la dinámica paleocultural regional.
Más de lo que se observa con una simple mirada: Mamíferos de los alrededores de Bahía Blanca
Luengos Vidal, Estela Maris; Baglioni, Joaquín
Los mamíferos, caracterizados fundamentalmente por la presencia de pelos y mamas, representan aquellos animales con que estamos mas familiarizados por ser nuestros compañeros diarios o por representar un recurso económico, mas aún en nuestra región agroganadera.
La bioinformática estructural o la realidad virtual de los medicamentos; Structural bioinformatics: the drugs virtual reality game
Marti, Marcelo Adrian; Turjanski, Adrian
La bioinformática estructural consiste, entre otras cosas, en realizar una simulación de del comportamiento de biomoléculas, principalmente proteínas y sus entornos, en diferentes situaciones. Al igual que un simulador de vuelo nos puede decir si un piloto se encuentra en condiciones de conducir con éxito un avión a su destino, la simulación con las biomoléculas puede establecer la capacidad de una droga para inhibir algunas enzimas o la posibilidad que dos proteínas puedan interactuar entre ellas. De este modo la bio informática contribuirá a un cambio en el paradigma del diseño de drogas permitiendo una mayor rapidez en su descubrimiento y en el proceso de optimización. Hay ejemplos exitosos de este nuevo paradigma como el caso de los inhibidores selectivos COX-2 como el Celecoxib usados en enfermedades inflamatorias crónicas, los inhibidores de la enzima convertidora de angiotensina (ECA) como el Captopril, empleados en el tratamiento de la hipertensión y diversos compuestos para el tratamiento del HIV.Palabras claves: bioinformática estructural – nuevo paradigma de desarrollo de medicamentos – diseño racional de fármacos – desarrollo de fármacos in silico.; Structural Bioinformatics consist in simulating biomolecules, mainly proteins and their environment in different situations. And just like a flight simulator can tell us, if a pilot is able to bring the plane safely to destiny, biomolecular simulations can determine the ability of a drug to inhibit certain enzyme, or the possibility of two proteins to interact with each other. In this way structural bioinformatics contributed to a change in the drug development paradigm allowing a faster drug discovery and optimization process. Successful examples of the new paradigm are COX-2 selective inhibitors used in chronic inflammations, ACE inhibitor captopril and several compounds to treat HIV among others.
