First record of Procyon cancrivorus (G. Cuvier, 1798) (Carnivora, Procyonidae) in stratigraphic context in the Late Pleistocene of Brazil Rodriguez, Sergio G.; Soibelzon, Leopoldo Héctor; Rodrigues, Shirlley; Morgan, Cecilia Clara; Bernardes, Camila; Avilla, Leonardo; Lynch, Eric Although five genera of procyonids are currently present in South America, only two of the extant genera, Procyon and Nasua are represented in the South American fossil record. A recent discovery of a procyonid lower second molar in Late Pleistocene deposits of Aurora do Tocantins, northern Brazil, offers potential to further our understanding of the stratigraphic and temporal range of South American fossil procyonids. We use geometric morphometric analysis of two-dimensional landmarks and semilandmarks to explore morphological variation in the lower second molars of extant Procyon lotor and Procyon cancrivorus and multivariate methods to support the identification of the Pleistocene specimen as P. cancrivorus. This material represents the second fossil record of P. cancrivorus in South America Procyonids entered South America in two phases: the first comprising by Cyonasua and Chapadmalania during the Late Miocene, and the other recent genera, beginning in the Late Pleistocene. These Late Miocene procyonids were more carnivorous than Late Pleistocene-Recent omnivorous taxa and possible went extinct due to competition with other placental carnivorans that entered South America and diversified during the latest Pliocene-Early Pleistocene.

An artificial neural network model for prediction of quality characteristics of apples during convective dehydration Di Scala, Karina Cecilia; Meschino, Gustavo; Vega Gálvez, Antonio; Lemus Mondaca, Roberto; Roura, Sara Ines; Mascheroni, Rodolfo Horacio In this study, the effects of hot-air drying conditions on color, water holding capacity, and total phenolic content of dried apple were investigated using artificial neural network as an intelligent modeling system. After that, a genetic algorithm was used to optimize the drying conditions. Apples were dried at different temperatures (40, 60, and 80 °C) and at three air flow-rates (0.5, 1, and 1.5 m/s). Applying the leave-one-out cross validation methodology, simulated and experimental data were in good agreement presenting an error < 2.4 %. Quality index optimal values were found at 62.9 °C and 1.0 m/s using genetic algorithm.

Genetic dissection of a motility-associated c-di-GMP signalling protein of Pseudomonas putida Österberg, Sofia ; Åberg, Anna ; Herrera Seitz, Karina; Wolf Watz, Magnus ; Shingler, Victoria Lack of the Pseudomonas putida PP2258 protein or its overexpression results in defective motility on solid media. The PP2258 protein is tripartite, possessing a PAS domain linked to two domains associated with turnover of c-di-GMP – a cyclic nucleotide that controls the switch between motile and sessile lifestyles. The second messenger c-di-GMP is produced by diguanylate cyclases and degraded by phosphodiesterases containing GGDEF and EAL or HD-GYP domains respectively. It is common for enzymes involved in c-di-GMP signalling to contain two domains with potentially opposing c-di-GMP turnover activities; however, usually one is degenerate and has been adopted to serve regulatory functions. Only a few proteins have previously been found to have dual enzymatic activities – being capable of both synthesizing and hydrolysing c-di-GMP. Here, using truncated and mutant derivatives of PP2258, we show that despite a lack of complete consensus in either the GGDEF or EAL motifs, the two c-di-GMP turnover domains can function independently of each other, and that the diguanylate cyclase activity is regulated by an inhibitory I-site within its GGDEF domain. Thus, motility-associated PP2258 can be added to the short list of bifunctional c-di-GMP signalling proteins.

Cold-set gelation of high pressure-treated soybean proteins Speroni Aguirre, Francisco José; Añon, Maria Cristina The ability of soybean proteins to form cold-set gels, using high pressure (HP) processing as denaturing agent and calcium incorporation was evaluated. Different protein preparations were assayed: soybean protein isolate (SPI), a b-conglycinin enriched fraction (7SEF) and a glycinin enriched fraction (11SEF). 7SEF formed aggregated gels with low water holding capacity whereas 11SEF did not form self-standing gels. SPI formed the better gels: ordered and with high water holding capacity. SPI gels were relatively soft and their visual aspect, rheological and texture properties, and water holding capacity depended on HP level (400e600 MPa), CaCl2 concentration (0.015e0.020 mol L 1) and protein concentration (85e95 g L 1), thus gels with different characteristics may be obtained. The gels comprised a three dimensional network stabilized by non-covalent interactions with spaces filled of proteins in aqueous solution. The results indicate that it is possible to use HP and subsequent calcium incorporation to form self-standing cold-set gels from soybean proteins. These gels may be of interest to incorporate heat-labile compounds or probiotics during the gelation step.

Elecciones escolares: moral y distinción en la relación escuela-familias; School choices: moral and distinction in the relation family-school; A escolha da escola: moral e distinção na relação família-escola Fuentes, Sebastián Gerardo En el contexto de la fragmentación educativa que caracteriza a la Argentina, este trabajo se propone analizar los modos en que se configura la relación escuela-familia en un grupo social de clase media-alta y alta. Las relaciones se analizan en función de las elecciones escolares que realizan familias de dos tradicionales localidades del Gran Buenos Aires sobre una escuela católica. Ese análisis está estructurado sobre el corpus analítico constituido por entrevistas a directivos, docentes, padres, y jóvenes exalumnos y por registros de observaciones participantes y documentación institucional. En esas elecciones escolares confluyen consideraciones estructuradas en un clima moral, valoraciones morales específicas y de distinción que tejen la relación escuelas-familias.; In the context of the educational fragmentation that characterizes the Argentina, this work proposes to analyze the manners in which is produced the relation family-school in a social group of upper-middle and upper class. The relations are analyzed depending on the school choices that realize families of two traditional localities of the Great Buenos Aires on a catholic school. This analysis is structured on the analytical corpus constituted for the principal's, teacher's, parent's and young's alumni interviews, and for records of participant observation and institutional documentation.; No contexto da fragmentação educativa que caracteriza a Argentina, este trabalho se propõe a analisar os modos pelos quais se configura a relação família-escola em um grupo social de classe média alta e alta. As relações são analisadas em função das escolhas que realizam as famílias de duas localidades tradicionais da Grande Buenos Aires de uma escola católica. A análise está ancorada num corpo analítico constituído por entrevistas a diretores, docentes, pais e jovens ex-alunos, por registros de observação participante e documentação institucional.

La opresión del capitalismo moderno: una reflexión sobre los nuevos métodos de selección de personal; The Oppression of Modern Capitalism: A Reflection on New Recruitment Methods Focas, Brenda Marisa Según las caracterizaciones de los sociólogos de la modernidad mercantilización, enajenación, racionalización, mediatización, fragmentación, burocratización y objetivación son una serie de tendencias crecientes que alejan a la cultura de las esferas subjetivas de las personas y llevan a concebir a los individuos y las relaciones sociales como si fueran cosas. En la actualidad, las exigencias para ser aceptado en un empleo son cada vez más denigrantes y la selección de postulantes adquiere un matiz perverso. A los exámenes de salud y psicológicos también se suman los llamados ?socio-ambientales?, que permiten ?conocer y evaluar al postulante en su domicilio" para observarlo dentro de su ámbito social, familiar, cultural y económico. Este artículo se propone mostrar, a partir de una serie de entrevistas a directivos de consultoras de Recursos Humanos, los criterios que se utilizan para la selección de personal en las medianas y grandes compañías. Además de una reflexión teórica sobre la situación de los empleados en la actualidad.; According to the descriptions given by modern sociologists, the growing trend of mercantilization, alienation, rationalization, mediatization, fragmentation, bureaucratization and objectification, moves culture away from people's subjective spheres, leading to the objectification of people and social relations. At present, job requirements are becoming more and more degrading, giving the recruitment process an evil nuance. To the health and psychological tests, we have to add the so called 'socio-environmental' test, used to 'know and assess the candidate at home', getting acquainted with their social, familiar, cultural and economic environments. This article aims at examining - based on different interviews with managers at Human Resources consultancies - the recruitment criteria used by medium and large companies. This study also includes a theoretical reflection on the current situation of employees.

Las columnas de Eduardo Mendicutti en "El Mundo". Travestismo y crítica cultural Bonatto, Adriana Virginia Desde 1988 Mendicutti colabora en el periódico El Mundo con una columna deopinión1 narrada por una voz ficticia femenina, La Susi, inspirada en la protagonista travesti de su primera novela, Una mala noche la tiene cualquiera, aparecida en 1982. En este trabajo analizaremos la serie publicada en la edición digital del diario entre mayo del 2000 y junio de 2001, ?La Susi en Gutenberg?, destinada a comentar acontecimientos y novedades relacionados con el ámbito literario y editorial español. Según nuestra lectura, el uso de la máscara y, específicamente, el juego del travestismo, funcionan a la manera de plataforma de enunciación que posibilita dar cuenta de la contingencia de cualquier sistema normativo.

Treinta años de políticas educativas y demanda sindical docente Southwell, Myriam Monica El rol del sindicalismo en la apertura democrática debe ser analizado en el marco del discurso de Alfonsín que alcanzó una particular fuerza con la denuncia del pacto militar-sindical.1 Esa importante denuncia marcaría el tono de la vinculación con el mundo sindical y eso se evidenció en que el gobierno no intentó articular a las organizaciones sindicales a su discurso de transición democrática sino vincularlas al pasado autoritario del país. En el posicionamiento gubernamental primaba la tradicional cercanía del sindicalismo a su oponente partido peronista, más que ningún otro aspecto, y sus resistencias para integrarlos a su discurso, debilitó a éste crecientemente.

Predictive Contribution of Personality Traits in a Socio-Cognitive Model of Academic Performance in Mathematics Cupani, Marcos; Pautassi, Ricardo Marcos Social Cognitive Career Theory (SCCT) explains academic performance as a function of conceptually distinct and interrelated cognitive variables. We aimed at extending SCCT?s performance model by examining the direct and indirect ? through socio-cognitive variables - contribution of personality traits on mathematics academic performance. Argentine youths (N = 543) were assessed in mathematics self-efficacy, outcome expectations, performance goals and skills. Personality traits were assessed through the Big Five Questionnaire for Children. Path analyses indicated that the contribution of personality on academic performance was mediated by socio-cognitive mechanisms. The results suggested that (a) students who exhibited higher Conscientiousness scores had higher self-efficacy beliefs and more positive outcome expectations and set more demanding performance goals, and (b) students who had higher Openness/Intellect scores exhibited higher self-efficacy beliefs. Gender did not moderate the relations among cognitive variables but influenced the association between personality traits and cognitive variables. Implications for teachers and guidance counselors are discussed.

El factor de la trasncripción WT-1 y su relación con el desarrollo de la injuria renal inducida durante la nefropatía obstructiva Mazzei, Luciana Jorgelina; Manucha, Walter Ariel Fernando El estudio del desarrollo renal sirve como un paradigma para comprender los mecanismos que son la base de la formación de un órgano. Múltiples genes desempeñan funciones trascendentes en el desarrollo renal temprano, entre los que se destaca WT-1. Se ha comprobado experimentalmente que la proteína WT1 en unos casos reprime y en otros activa la transcripción de numerosos genes, pero sus dianas fisiológicas son poco conocidas. Recientes investigaciones genéticas han permitido caracterizar muchas de las complejas interacciones entre los componentes individuales, sin embargo la concreción de nuevos experimentos bioquímicos, moleculares y funcionales como los propuestos en nuestro y otros laboratorios de investigación, nos permitirán establecer con mayor profundidad el grado de compromiso entre las proteínas participantes y las posibles consecuencias fisiopatogénicas de su desacople

Resistive switching in ferromagnetic La2/3Ca1/3MnO3 thin films Alposta, Ignacio; Kalstein, Ariel; Ghenzi, Néstor; Bengió, Silvina; Zampieri, Guillermo Enrique; Rubi, Diego; Levy, Pablo Eduardo Ferromagnetic thin films of La_{2/3}Ca_{1/3}MnO_{3} manganite were grown by pulsed laser deposition, under different oxygen atmospheres, on silicon substrates.We performed structural, magnetic, spectroscopic, and electrical characterization of the films. Resistive switching between high and low resistance states was obtained upon pulsing with opposite polarities voltages. The I-V curves exhibit sharp transitions between these states. The RS properties are strongly dependant on the films oxygen stochiometry and on the compliance current used for producing the high to low transition. ON/OFF ratios as high as 1000 were obtained for optimal RS conditions. Obtained results are discussed within the framework of mobile oxygen vacancies.

Effect of structural modifications on the drying kinetics of foods: changes in volume, surface area and product shape de Michelis, Antonio; Marquez, Carlos Alberto; Mabellini, Alejandra; Ohaco, Elizabeth; Giner, Sergio Adrian Macro and micro-structural changes take place during food dehydration. Macro-structural changes encompass modifications in shape, area and volume. Studies of such changes are important because dehydration kinetics (essential for calculating industrial dryers) may be highly influenced by changes in food shape and dimensions. The overall changes in volume, surface area (?shrinkage?) and shape (Heywood factor, with provides a close description of food shape) were determined experimentally, and the results were correlated with simple expressions. Hence, although dehydration kinetics can be modeled with simplified overall shrinkage expressions, the possibility of selecting a suitable geometry and predicting the characteristics dimensions will provide higher accuracy. An additional unresolved problem is the lack of a general model that predicts macro-structural changes for various foods and diverse geometries. In this work, based on experimental data of sweet and sour cherries, and rose hip fruits, a simplified general model to predict changes in volume and surface area are proposed. To estimate how the changes in characteristic dimensions affect the kinetic studies, experimental drying curves for the three fruits by means of a diffusional model considered the following variants for the characteristic dimensions: (i) The radius of the fresh food, assumed constant; (ii) The radius of the partially dehydrated product; (iii) The radius predicted by the correlation for structural changes, especially volume, obtained in this work and generalized for the three fruits, and (iv) to demonstrate the need to study the macro-structural changes for all dehydrated foods, also be present the case of a restructured food.

The Farallon-Aluk ridge collision with South America: Implications for the geochemical changes of slab window magmas from fore- to back-arc Aragon, Eugenio; Pinotti, Lucio Pedro; D'eramo, Fernando Javier; Castro, Antonio; Rabbia, Osvaldo Miguel; Coniglio, Jorge Enrique; Demartis, Manuel; Hernando, Irene Raquel; Cavarozzi, Claudia Ernestina; Aguilera, Emilia Yolanda The collision of a divergent ocean ridge may evolve into two end cases: in the continuity of ocean-floor subduction, or in the detachment of the subducted plate. The northern Patagonia active plate margin has the unique situation that in Cenozoic time it has been subjected to two divergent ridge collisions, each one representing one of the end members. The Neogene Antarctica-Nazca divergent ridge collision evolved as a continuous ocean-floor subduction system, promoting a magmatic hiatus at the arc axis, the obduction of part of the ridge ocean-floor in the fore-arc, and basaltic volcanism in the back-arc. In contrast, the Paleogene Farallon-Aluk divergent ridge collision evolved into a transform margin, with the detachment and sinking of the Aluk plate and the development of a large slab window. As in the previous case, this collision promoted a magmatic hiatus at the arc axis, but the tectono-magmatic scenario changed to postorogenic synextensional volcanism that spread to the former fore-arc (basalt, andesite, rhyolite) and former back-arc (bimodal ignimbrite flare-up, basalt). Geochemistry of this slab window synextensional volcanism shows more MORB-like basalts towards the former fore-arc, and MORB-OIB-like basalts towards the former back-arc. Instead, an isolated undeformable crustal block in the former back-arc, with an ?epeirogenic? response to the slab window and extensional regime, was covered by OIB-type basalts after uplift. Major elements show that slab window basalts reach TiO2 values up to 3 wt%, as compared with the top value of 1.5 wt% of arc magmas. Besides, the MgO with respect to (FeOt + Al2O3) ratio helps to distinguish slab window magma changes from the former fore-arc to the former back-arc and also with respect to the ?epeirogenic? block. Higher contents of HFS elements such as Nb and Ta also help to distinguish this slab window from arc magmas and also, to distinguish slab window magma changes from the former fore-arc to the former back-arc and ?epeirogenic? block settings. The isotope compositions of slab window magmatism show a disparate coeval array from MORB to crustal sources, interpreted as a consequence of the lack of protracted storage and homogenization due to the extensional setting.

Evaluación del riesgo de impacto ambiental de plaguicidas en cultivos anuales del centro de Santa Fe; Assessment of pesticide environmental risks in annual crops in center of Santa Fe Arregui, Maria Cristina; Grenon, Daniel Arnaldo; Sánchez, D.; Ghione, J. Los plaguicidas permiten alcanzar la productividad y la sustentabilidad si se manejan adecuadamente. La elaboración de indicadores permite cuantificar el impacto ambiental de un fitosanitario. El objetivo de este trabajo fue determinar el impacto ambiental de plaguicidas sobre el suelo y el agua en lotes de agricultura del centro de Santa Fe con tres indicadores: GUS, Ipest e Índice relativo de Plaguicidas. El trabajo se realizó en 25 establecimientos cuyos registros de aplicaciones en cultivos de soja, maíz y trigo se relevaron entre 2007 y 2011. Se calcularon los tres indicadores y se compararon los resultados obtenidos. El maíz fue el cultivo con mayor riesgo de impacto ambiental por el uso intensivo de atrazina. En trigo y soja, los ingredientes activos empleados tuvieron bajo impacto ambiental. El empleo de indicadores contribuye a seleccionar plaguicidas con mejor comportamiento ambiental y realizar una planificación más sustentable de los cultivos.; Pesticides are essential tools to achieve productivity and sustainability in agricultural crops when they are applied minimizing undesirable effects. Pesticide environmental impact is related to toxicity and time of exposure. Several indicators allow the calculation of this impact: GUS, IPEST and Relative Pesticide Index. Our aim was the evaluation of pesticide environmental impact on soil and water in agricultural fields of Central Santa Fe with those three indicators. All pesticide treatments applied in soybean, wheat and corn in 25 farms were recorded from 2007 and 2011, also with soil properties and pesticide characteristics. Indicators were calculated and the results were compared. Corn has the highest risk of pesticide contamination in soil and water, related to the frequent use of atrazine. Wheat and soybean had less environmental impact. The application of indicators may be helpful for considering the use of new active ingredients and their relationship with sustainable systems.

Radiocarbon chronology of the early human occupation of Argentina Prates, Luciano Raúl; Politis, Gustavo Gabriel; Steele, James This paper reports the compilation and initial analysis of a database of 14C dates from archaeological sites in Argentina for the period 13,000 and 7000 14C BP. The spatial and temporal distribution of human occupation evidence during this period is surveyed, with discussion of potential sampling biases affecting the recognition of such sites in each region of Argentina. The archaeological signal of human occupation at the beginning of this period (13,000-11,000 14C BP) is suggestive but sparse, and weak. However, from about 11,000 14C BP there is a consistent archaeological signal. Most of the earliest occupation evidence comes from the eastern Pampas and from southern Patagonia. In the Chaco and Northeast regions, similarly early archaeological sites have not yet been detected. This contrast may reflect the actual distribution of early human occupation, but it may also reflect biased research effort and/or systemic factors affecting the visibility and level of preservation of the early archaeological record. In other regions such as the eastern slope of the Andes in Patagonia, the peri-Andean Central West, and the Northwest, where there has been intensive archaeological research for an extended period and there are fewer systematic factors which are likely to bias archaeological visibility, the absence of archaeological evidence of early occupation may indicate delayed colonization of these more marginal environments. The conclusion discusses the implications of 14C dates associated with Fishtail Projectile Points for the western hemisphere pre-Clovis debate, and the implications of terminal Pleistocene/early Holocene dated remains of extinct mammals for the megafaunal overkill hypothesis.

XRCC2 R188H (rs3218536), XRCC3 T241M (rs861539) and R243H (rs77381814) single nucleotide polymorphisms in cervical cancer risk Perez, Luis Orlando; Crivaro, Andrea Natalia; Barbisan, Gisela; Poleri, Lucía Belén; Golijow, Carlos Daniel Human Papillomavirus (HPV) is the main cause of cervical cancer and its precursor lesions. Transformation may be induced by several mechanisms, including oncogene activation and genome instability. Individual differences in DNA damage recognition and repair have been hypothesized to influence cervical cancer risk. The aim of this study was to evaluate whether the double strand break gene polymorphisms XRCC2 R188H G>A (rs3218536), XRCC3 T241M C>T (rs861539) and R243H G>A (rs77381814) are associated to cervical cancer in Argentine women. A case control study consisting of 322 samples (205 cases and 117 controls) was carried out. HPV DNA detection was performed by PCR and genotyping of positive samples by EIA (enzyme immunoassay). XRCC2 and 3 polymorphisms were determined by pyrosequencing. The HPV-adjusted odds ratio (OR) of XRCC2 188 GG/AG genotypes was OR = 2.4 (CI = 1.1-4.9, p = 0.02) for cervical cancer. In contrast, there was no increased risk for cervical cancer with XRCC3 241 TT/CC genotypes (OR = 0.48; CI = 0.2-1; p = 0.1) or XRCC3 241 CT/CC (OR = 0.87; CI = 0.52-1.4; p = 0.6). Regarding XRCC3 R243H, the G allele was almost fixed in the population studied. In conclusion, although the sample size was modest, the present data indicate a statistical association between cervical cancer and XRCC2 R188H polymorphism. Future studies are needed to confirm these findings.

Nuevos registros de Hippidion (Mammalia, Perissodactyla) en el Pleistoceno tardío de la Provincia de Buenos Aires, Argentina; New record of Hippidion (Mammalia Perissodactyla) from the late Pleistocene of Buenos Aires province, Argentina Prado, Jose Luis; Bonnini, R.; Alberdi, M. T.; Scanferla, Carlos Agustín; Pomi, Lucas Horacio; Fucks, Enrique Eduardo En este estudio se describen dos nuevos cráneos referidos a Hippidion principale (Lund) y varios elementos del esqueleto apendicular referidos a H. devillei procedentes de dos localidades clásicas de la provincia de Buenos Aires, las márgenes de los ríos Salado y Quequén Grande. Para la identificación taxonómica de los restos apendiculares, se realizó un análisis multivariante en el que se incluyeron los metacarpianos y falanges descritos y los registrados en varias localidades de Argentina y Brasil. Para la determinación de los cráneos se realizó un estudio comparativo con otros cráneos de diversas localidades.
Estos hallazgos incrementan el registro de Hippidion en América del Sur y aportan nuevas evidencias sobre la cronología de sus especies en Argentina. Se realizó una datación por AMS para el ejemplar de Río Salado (MHM-P54) que ha suministrado una edad 14C 14120 ± 50 BP. En general, los sedimentos portadores en ambas localidades son referibles a la Edad Lujanense, Biozona de Equus (Amerhippus) neogeus.; This study describes two new skulls referred to Hippidion(Lund) and various elements of the appendicular skeleton referred to H. devillei from two classic localities from Buenos Aires province: the Salado and Quequén Grande Rivers. For taxonomic identification of the appendicular remains was performed a multivariate analysis that included the metacarpals and phalanges described and several remains recorded in various locations in Argentina and Brazil. For the determination of the skulls was made a comparative study with other skulls from different localities. These data increasing the record of Hippidion in South America and provide new evidence about the chronological distribution of two species of Hippidion. One radiometric data was obtained by the method of AMS dating to the skull from Salado River (MHM-P54) about a 14C age 14120 ± 50 BP. In general, bearing sediments at both localities are referable to the Lujanian Age and the Biozone of Equus (Amerhippus) neogeus.

Trayectorias de relaciones en el marco de luchas étnico - territoriales en la Patagonia Argentina Crespo, Carolina Flavia; Tozzini, María Alma En este artículo abordamos los vínculos que se establecieron entre comunidades mapuches y algunas organizaciones sociales a partir de la conformación de reclamos étnico-territoriales en Lago Puelo –noroeste de la provincia de Chubut, Patagonia Argentina–. En particular, analizamos las relaciones que se entablaron con organizaciones indígenas mapuche-tehuelche y con una organización socio-ecologista no indígena. Esta trama de relaciones está dando textura y sentido a la dinámica que ha adoptado la auto-adscripción indígena, las memorias activadas y las formas de lucha.; In this article we examine some of new links established between Mapuche communities and social organizations from the conformation of ethno-territorial claims in Puelo Lake –northwest of the province of Chubut, Patagonia Argentina–. In particular, we analyze the relationships that had been engaging with indigenous mapuche – tehuelche organizations and a socio- ecological non-indigenous organization. This relationships are giving texture and sense to the dynamics that has adopted the indigenous self-identification, the activated memories and the tested forms of struggle.; Dans cet article, nous abordons les liens établis entre les communautés mapuches et les organisations sociales, comme consequence des revendications ethno-territoriales au Lago Puelo, au nord-ouest de la province du Chubut, dans la Patagonie Argentine. En particulier, nous analysons les rapports qui ont été établies entre des indigènes Mapuche-tehuelche avec une organisation socio-écologique non autochtone. Ce réseau de relations veut donner un sens à la texture et la dynamique qui ont adopté les auto-attributions indigènes, les mémoires activées et les formes de lutte.

Turbidimetric Behavior of Colloidal Particles in Beer Before Filtration Process Benitez, Elisa Ines; Martinez Amezaga, Nancy María Jimena; Sosa, Gladis Laura; Peruchena, Nelida Maria; Lozano, Jorge Enrique The effect of colloidal particles and yeast on turbidity of Pilsen beer before the filtration process was studied in this work. The colloidal particles are mainly composed of polysaccharides, representing 96.89 %, in second place proteins with a concentration close to 2 %, and polyphenols less than 0.3 %. There is also a very low concentration of yeast (;lt;0.25 %). The presence of different types of particles in the sample caused multimodal histogram in the particle size distribution and four distinct zones were identified: (1) very small individual particles (D = 0.06μm),(2) yeast(D = 3μm) (3) colloidal aggregates (D = 17μ), and (4) a zone with a high dispersion of size, with two D Values (101 and 200 μm). Particles size counts well correlate with both the scanning electron microscopy (SEM) digital image analysis, and the turbidity determination. The fractal dimension (Df) of the aggregates was determined by analyzing the SEM images with the Variogram method, obtaining Df > 2.4 values. Those values are typical of aggregates formed by rapid flocculation or diffusion limited aggregation. Results of this study support the formulation of a model valid for the prediction of colloidal particles concentration in beer. © 2012 Springer Science+Business Media, LLC.

China: el país de los senderos que se bifurcan Rapoport, Mario Daniel La noción de países emergentes la plantea, para el siglo XIX, Paul Bairoch en Mythes et paradoxes de l’histoire économique, a fin de rebatir la idea de que solamente reinaba entonces la pax britannica. Por un lado, reconoce la importancia del imperio británico y la existencia de una división internacional del trabajo basada en el libre cambio, con el liderazgo y monopolio industrial del Reino Unido y la participación en él de países proveedores de alimentos o materias primas, como la Argentina. Pero, dice Bairoch, había también países emergentes, proteccionistas e industrialistas, como los Estados Unidos y Alemania, que hacia fines de siglo superaban ya en producción, innovaciones tecnológicas e incluso en el intercambio de muchos productos, a la primera gran metrópoli industrial. Según Bairoch, el que hoy llamamos mundo desarrollado, salvo Gran Bretaña, era un “océano de proteccionismo”, mientras que aquellos países que giraban en la órbita británica, como la Argentina, se habían convertido en un “océano de liberalismo”.