¿Un exorcismo en el convento de Santa Catalina durante el siglo XIX (Buenos Aires)? Schavelzon Chavin, Daniel Gaston En trabajos de arqueología de rescate en un convento construido en el siglo XVIII se encontró un pozo con un objeto metálico que representaba un Macho Cabrío, con cornamenta y alas. Este había sido quemado y enterrado en un evento de difícil explicación. Se puede suponer que, si bien pertenecía a un macetero francés usado como ornamento en su época, ese fragmento, grande y pesado, pudo interpretarse como una imagen diabólica y por ende fuera fruto de algún evento de exorcismo entre las monjas del convento.; During the rescue archaeological operations at the Santa Catalina nuns’ convent on Buenos Aires, a pit was discovered. In it an iron figure with diabolic reminiscence was fired and buried. The figure was an ornament from a French sculpture; but what we fund was probably part of an exorcism ritual developed on the central patio of the convent during the second half of XIXth century.

Alan Berliner, Ross McElwee, Michael Moore y Lourdes Portillo: El documental subjetivo, una vertiente contemporánea y productiva Piedras, Pablo El presente artículo se aboca al análisis de una tendencia que se ha tornado progresivamente dominante en el documental de las últimas dos décadas: la inscripción de la subjetividad del realizador en las representaciones de no-ficción. En esta oportunidad, nos acercaremos a la obra de tres documentalistas norteamericanos que han hecho de la incorporación del «yo» el centro de sus narrativas, aunque desde poéticas particulares y distinguibles. De forma completaria, analizaremos el caso de Lourdes Portillo, documentalista mexicana radicada en los Estados Unidos.

Las primeras reflexiones sobre la ciencia y la tecnología en la Argentina: 1968-1973; The first thinking on science and technology in Argentina : 1968-1973 Feld, Adriana El objetivo de este artículo es analizar el modo en que, entre fines de la década de 1960 y principios de la siguiente, la ciencia y la tecnología fueron retematizadas en la arena pública como un asunto estratégico. Para eso se considerarán dos grandes vertientes ideológicas que tienen consecuencias teórico-conceptuales y normativas divergentes: una más radical, cuyo representante emblemático fue Oscar Varsavsky, puesto que cuestionó tanto el núcleo duro de la ciencia (sus prácticas, sus agendas, sus modos de financiamiento, sus métodos, etc.), como también el orden social vigente; una vertiente más moderada, que en la definición/estigmatización de Varsavsky ha sido asimilada a las ideas “desarrollistas”, en las que se destacan los trabajos y reflexiones de autores como Jorge Sabato, Amílcar Herrera, Jorge Katz, Carlos Mallmann y Alberto Aráoz. El análisis de las diversas perspectivas se enmarcará, a su vez, en un proceso de creación de espacios institucionales para la discusión y producción de conocimiento acerca de la ciencia y la tecnología, como la Fundación Bariloche, el Instituto Torcuato Di Tella, la revista Ciencia Nueva y, en el ámbito internacional, en la interlocución con diversos organismos, en particular la Unesco y la OEA.; The aim of this paper is to analyze how ‘science and technology’ have been re-thematized in the public arena as a strategic issue between the end of the 60’s and the beginning of the 70’s. To do so, we will consider two main ideological streams that implied divergent theoretical, conceptual and normative consequences: one of them, more ‘radical’, whose emblematic representative was Oscar Varsavsky, who questioned both the hard core of sciences (practices, agendas, ways of financing, methods, etc.) and the dominant social order; another stream, more ‘moderate’ (Varsavsky has defined/stigmatized it as a thought close to “desarrollismo”), integrated by the works of several authors, like Jorge Sabato, Amílcar Herrera, Jorge Katz, Carlos Mallmann y Alberto Aráoz. The analysis of these perspectives will be framed by the highlighting of a process of creation of diverse institutional spaces for debates and knowledge production on science and technology, such as Fundación Bariloche, the Institute Torcuato Di Tella, the journal Ciencia Nueva and, in the international context, the dialogue with several organism, particularly the Unesco and the OAS.

La condición postmoderna en Lyotard Colella, Leonardo Javier Jean-François Lyotard nació en Versalles en 1924 y murió en París en 1998. Fue profesor en la Universidad de Paris VIII, miembro del Collége de France y profesor emérito de la Universidad de París. El filósofo francés es reconocido por su estudio sobre el postmodernismo a finales de la década de 1970. Antes fue miembro de Socialisme ou Barbarie, un grupo de izquierda crítica conformado por diversos intelectuales franceses. Lyotard señaló que el discurso humano ocurre en un variado número de dominios inconmensurables, y que la época de los grandes relatos que intentaban dar sentido a la historia había sido dejada atrás. Asimismo, criticó los metadiscursos idealistas, iluministas, cristianos, marxistas y liberales. Afirmó que la cultura postmoderna se caracteriza por la incredulidad con respecto a los metarrelatos. Y fue un defensor de la pluralidad cultural y de la diversidad. En 1979, publica La condición postmoderna: informe sobre el saber. Este escrito surgió inicialmente como un informe sobre la condición actual del saber a pedido de las autoridades universitarias canadienses de Québec, y a raíz de la trascendencia obtenida fue posteriormente publicado. En la obra, el autor intenta analizar el concepto teórico postmoderno desde una perspectiva filosófica, y diagnosticar los cambios producidos durante el siglo XX. El trabajo de Lyotard tiene por objeto el saber en las sociedades desarrolladas contemporáneas. A continuación, se expone un detallado análisis de la obra, examinando uno a uno los capítulos que la componen. Y finalmente se presenta una de las repercusiones que tuvo la obra, describiendo el debate con Jürgen Habermas.

Patrimonio arqueológico, memoria y territorio. Procesos de autoctonización entre los mapuches de Lago Puelo, Chubut (Patagonia, Argentina); Archaeological Heritage, Memory and Territory. Authoctonization Processes in Mapuche’s People of Lago Puelo, Chubut (Patagonia, Argentina) Crespo, Carolina Flavia Este artículo analiza las disputas de sentido que se configuran en torno de la categoría de “autoctonía” en la localidad de Lago Puelo –Comarca Andina del Paralelo 42º, noroeste de Chubut, Patagonia, Argentina–, su articulación con determinados derechos y demandas de la población mapuche y el lugar que ocupa el patrimonio arqueológico en el proceso de autoctonización de esta población dentro de procesos hegemónicos cambiantes. Tal forma de categorización resulta central en las modalidades de construcción de identidades políticas de los pueblos indígenas, de configuración de sus demandas y de las políticas estatales de reconocimiento de derechos hacia estos pueblos.; This article analyzes the discussions of the meaning of the categories of “authoctony” nowadays in Lago Puelo –the Andean Administrative Division o of the 42nd Parallel , northeast of Chubut, in Patagonia, Argentina–, its link with certain rights and demands of the Mapuche people and the role of archaeological heritage in the process of this authocthonization within changing hegemonic processes. This form of categorization is central to the construction of the political identities of indigenous people and the configuration of their demands as well as public policies designed to acknowledge their rights.

“Casualidades” y “causalidades” de los procesos de patrimonialización en la provincia de Santa Cruz Rodriguez, Mariela Eva En la provincia de Santa Cruz (Argentina), los discursos hegemónicos suelen sostener que "no hay indios" fundamentando tal enunciado en que los mapuche son ajenos a la provincia ("indios chilenos" que "vinieron después") y que los tehuelche (considerados como los "verdaderos indios argentinos", los "originarios de Santa Cruz", "se extinguieron" o "se mezclaron". Este trabajo se centra en los efectos de los dispositivos patrimonializadores que actuaron de manera diferencial para uno y otro pueblo indígena, en los cuales intervinieron discursos y prácticas científicas y normativas enmarcadas en matrices ideológicas evolucionistas, civilizatorias, racistas y nacionalistas. El argumento de este ensayo es que, al invisibilizar la presencia mapuche y apropiar a los tehuelche como "nuestros indios, nuestros ancestros", las políticas de protección y rescate patrimonial mantienen una continuidad con dispositivos científicos coloniales en el marco de un régimen democrático que camufla actos de violencia en términos aparentemente inocuos como "tradición", "cultura", "folklore". Es decir, al borrar los efectos del "legado colonial", dichas políticas silencian situaciones de explotación y subordinación y, simultáneamente, niegan a los indígenas agencia y creatividad. Paradójicamente, estas dependencias administrativas (secretarías y direcciones de cultura), constituyen actualmente el principal espacio de interlocución entre indígenas, funcionarios y académicos, al que recientemente (2010) se sumó el Consejo de Educación mediante la creación de la Modalidad de Educación Intercultural Bilingüe. En el contexto actual de emergente autoafirmación y reorganización indígena en Santa Cruz, este trabajo tiene un doble objetivo: analizar algunos de los dispositivos patrimonializadores que entran en tensión con las reapropiaciones, impugnaciones y demandas de reconocimiento de su existencia y preexistencia étnica y cultural y reflexionar sobre las consecuencias de los posicionamientos epistemológicos, éticos y políticos de la práctica profesional académica, particularmente de la antropología, entendida con sus múltiples orientaciones (arqueológica, física, lingüística, social, histórica, etc.).

La revolución mexicana y sus fantasmas: ¿cómo narrar la violencia? (con motivo del centenario) Quintana, Isabel Alicia En nuestro trabajo nos proponemos analizar una serie de narrativas en torno a los problemas de la representación de la historia y de la identidad mexicana. Dicha cuestión, nos conduce a repensar las nociones de comunidad y territorio a partir de la emergencia de diferentes momentos de crisis institucionales y sociales. Nos interesa ver cómo momentos complejos del acontecer histórico mexicano (y que retornan constantemente en las representaciones estéticas, culturales y en las reflexiones intelectuales), tales como la Revolución Mexicana, el levantamiento cristero, la institucionalización de la revolución ( lo que para algunos supuso la traición de los ideales defendidos por la misma), la consolidación de una economía neoliberal producen problemas en el orden de la representación simbólica y textual; es decir, se fisura el marco para la articulación de algún sentido frente a el resquebrajamiento de las certidumbres vigentes. En ese sentido, una de las cuestiones que se repiten en los textos es la escenificación de la violencia política y racial en la que se funda el acuerdo social al dramatizar las aporías que subyacen al ideal contractualista, tanto en la literatura sobre la Revolución Mexicana, como en la que retoma dicho tema en momentos históricos diferentes (período de institucionalización de la revolución, decadencia y crisis del PRI).

Between the voices of the state and the human rights movement: Never again and the memories of the disappeared in Argentina Crenzel, Emilio Ariel This paper analyzes the Nunca Más (Never Again) report issued by the National Commission on the Disappearance of Persons (CONADEP), created by constitutional President Raúl Alfonsín in 1983 to investigate the thousands of forced disappearances perpetrated in Argentina. Nunca Más provided a new interpretation of the country’s recent violent past, which combined Alfonsín’s intention to bring the perpetrators of political violence to trial with the humanitarian narrative forged by victims of the disappeared during the dictatorship. In doing so, the Report denounced the political repression, redefined the magnitude of the disappearances, and held the Armed Forces officially responsible for the human rights violations. CONADEP’s investigation and the Nunca Más report had a significant impact worldwide. As the first truth commission and report to expose human rights violations in the context of Latin America’s democratization processes, governments and human rights organizations viewed them as models for exposing the political violence suffered by these societies in the 1970s and 1980s. As a result, ‘truth commissions’ and their reports became the main vehicles for the construction of historical truth in several countries across the continent—many of them even using the title “Never Again”—and the production of transitional justice policies.

La influencia del contexto en el aprendizaje de la Física: Un estudio con padres de estudiantes de nivel secundario Mazzitelli, Claudia Alejandra En este trabajo se presenta un estudio exploratorio realizado con padres de estudiantes de nivel secundario con el objetivo de identificar y analizar, desde un abordaje psicosocial, sus opiniones y actitudes hacia la enseñanza y el aprendizaje de la Física y sus conocimientos cotidianos sobre algunos fenómenos físicos. Para esto se trabajó con un grupo de padres que participó voluntariamente. Los mismos respondieron una encuesta en la que se les solicitó información sobre algunas variables de base y socioculturales (sexo, edad, nivel de instrucción, ocupación); se indagaron sus opiniones sobre la Física, su enseñanza y su aprendizaje y, además, respondieron una prueba para la detección de estructuras conceptuales sobre movimiento. A partir de los resultados obtenidos se ha analizado la influencia que tendrían estas representaciones del contexto familiar en el aprendizaje de la Física.; This work presents an exploratory study made with the parents of high school students with the aim of identifying and analyzing, from a boarding psychosocial, their opinions and attitudes towards the teaching and learning of Physics and their common knowledge about some physical phenomena. The work was carried out with a sample of parents who participated voluntarily. First, they were asked to complete a questionnaire with information about some basic and social-cultural variables (sex, age, educational level, occupation); then, their opinions about Physics, its teaching and learning, were inquired; finally, they made a test for the detection of conceptual structures about movement. From the results obtained, we have analyzed the influence that these representations of the family context would have in the learning of Physics.

Mesotheriid (Mammalia, Notoungulata) remains from the Colhuehuapian beds (Early Miocene) of Chichinales Formation, Río Negro Province, Argentina Paz, Ernesto Rodrigo; Kramarz, Alejandro Gustavo; Bond, Mariano The Mesotheriidae represent one of several clades of the endemic South American ungulate Order †Notoungulata. This clade has some rodent-like adaptations such as hypertrophied upper and lower incisors, highly hypsodont cheek teeth, reduced dental formula (in younger forms), simplified occlusal morphology, and specialized zygomasseteric structure, among other features (Patterson, 1934; Billet et al., 2008). Traditionally, the Mesotheriidae have been divided into two subfamilies: Trachytheriinae and Mesotheriinae (Simpson, 1945). Recent phylogenetic analyses supported the monophyly of Mesotheriinae, but indicated that Trachytheriinae is a paraphyletic assemblage of basal mesotheriids (Cerdeño and Montalvo, 2001; Croft et al., 2004; Reguero and Castro, 2004; Billet et al., 2008).

Development of a highly specific ensemble of topological models for early identification of P-glycoprotein substrates Di Ianni, Mauricio Emiliano; Talevi, Alan; Castro, Eduardo Alberto; Bruno Blanch, Luis Enrique P-glycoprotein (Pgp) is an ATP-dependent efflux transporter protein associated with multidrug resistance in several diseases such as cancer, epilepsy and AIDS. It is preferentially expressed in organs and tissues that function as a barrier (e.g. the gut walls or the blood?brain barrier) or promote the elimination of xenobiotics from the organism (e.g. liver and kidney). Pgp limits drug bioavailability; thus, the recognition of Pgp substrates at the early stages of the drug development cycle is essential for the development of new chemotherapeutic agents to deal with multidrug resistance issues. Here we present the development of several classifier models based on topological descriptors to identify potential Pgp substrates, aimed to be applied as secondary filter in virtual screening campaigns. Receiver Operating characteristic (ROC) curves show that combination of individual models, through data fusion, in a three-model ensemble, allows attaining higher areas under the curve and an overall better behavior in terms of sensitivity or specificity. The individual discriminant functions (dfs) presented have a performance similar to that of the previously reported models and, remarkably, our models only include low-dimensional (up to 2D) molecular descriptors, which makes them adequate for the virtual screening of increasingly large virtual chemical repositories.

Marine vertebrate assemblages in the southwest Atlantic during the Miocene Cione, Alberto Luis; Cozzuol, Mario Alberto; Dozo, Maria Teresa; Acosta Hospitaleche, Carolina Ileana Alicia Two biogeographical units are generally recognized in the present shelf area of Argentina: the Magellanian andArgentinian Provinces. The two provinces differ in their fossil record. The evolution of these provinces has beencharacterized by migrations, extinctions, pseudoextinctions and, perhaps, even speciation events. Marine vertebrateassemblages with some similarities to the Argentinian fauna were already present in the Miocene, whereasno associations similar to those of the Magellanian fauna have been found in South America before the Pleistocene.Two successive major marine transgressions flooded northern Patagonia during the Miocene: the ‘Patagoniense’(Early Miocene) and the ‘Entrerriense’ (Middle to Late Miocene). We analyse three rich fossil assemblages thatwere formed during these transgressions. The absence of Magellanian Miocene vertebrate assemblages is consistentwith the hypothesis of a more southern distribution of the cold-temperate fauna at that time. In Patagonia,as in other regions, an increased number of living groups appeared from the Lower to Upper Miocene. The LateMiocene aquatic mammals had a modern aspect, and some of the fish species are still living in the South AtlanticOcean. In this contribution, we stress that warm-temperate fishes and a high diversity of penguins are foundtogether at the base of the Gaiman Formation. We hypothesize that penguins were adapted to live in warmerwaters than those of the latest Cenozoic and the Recent. Finally, we recall that many taxa became extirpatedbecause of the global temperature drops of the late Cenozoic.

Pharmacocinétique et biodisponibilité de fosfomycine chez le poulet de chair; Pharmacokinetics and bioavailability of fosfomycin in broiler chicken Soraci, Alejandro Luis; Pérez, Denisa Soledad; Tapia, Maria Ofelia; Martinez, Guadalupe; Dieguez, Susana Nelly; Buronfosse Roque Florence; Harkes, Roberto; Colusi, A.; Romano Omar La pharmacocinétique et biodisponibilité de deux formulations de fosfomycine (fosfomycine disodique et fosfomycine calcique) ont été étudiées chez le poulet de chair. Les concentrations plasmatiques de fosfomycine ont été mesurées par chromatographie liquide haute performance (HPLC) couplée à une spectrométrie de masse en tandem (HPLC – SM/SM). Après administration d’un bolus intraveineux, la demi-vie d’élimination chez le poulet de chair est environ 1,4 h et le volume de distribution 231 ml/kg. Après absorption de fosfomycine par voie orale les valeurs de Cmax, Tmax, AUC(0-24) et biodisponibilité (F) sont respectivement 29,8 µg/ml, 2,0 h, 125 µg.h/ml et 39,3 %. Après l’administration par voie intramusculaire, les valeurs obtenues sont 20,7 µg/ml, 0,8 h, 65,1 µg.h/ml et 82 % pour la Cmax, Tmax, AUC(0-24) et biodisponibilité (F) respectivement. En considérant une CIM90= 8 µg/ml pour la fosfomycine sur des souches de E.coli chez le poulet de chair, les rapports AUC0-24/CMI90 calculés pour la fosfomycine administrée par voie orale et intramusculaire sont de 15,6 et 8,1 ce qui suggère une efficacité thérapeutique insuffisante in vivo lors d'une administration unique. Pour cette raison, il a été récemment proposé d’utiliser sur des souches sensibles de E.coli, une dose orale de charge de 40 mg/kg de fosfomycine disodique administrée dans l'eau de boisson, suivie d'une nouvelle administration de 40 mg/kg 8 h plus tard (soit 80 mg/kg par jour).; The pharmacokinetics and the bioavailability of fosfomycin salts (sodium fosfomycin and calcium fosfomycin) were studied in broiler chickens after intravenous, intramuscular and oral administration. Plasma concentrations were measured by high performance liquid ms/ms. After IV administration the area under the fosfomycin concentration: time curve in plasma was AUC(0-24) of 318 µg.h/ml and the volume of distribution (Vd) of 231 ml/kg. The elimination was rapid with a plasma clearance of 115 ml/kg/hr and a T1/2 of 1.4 h. Peak plasmatic concentration (Cmax), Tmax, AUC(0-24) and bioavailability for the oral administration (40 mg/kg) were 29.8 µg/ml, 2.0 h, 125 µg.h/ml and 39.3% respectively. Peak plasmatic concentration (Cmax), Tmax, AUC(0-24) and bioavailability for the IM administration (10 mg/kg) were 20.7 µg/ml, 0.8 h, 65.1 µg.h/ml and 82% respectively. Considering a minimum inhibitory concentration (MIC90) of 8 µg/ml for fosfomycin on E.coli in broilers, the ratios AUC0-24/CMI90 estimated for fosfomycin after oral and IM administrations were 15.6 and 8.1 respectively. This suggests an insufficient therapeutic efficacy in vivo when administered in a unique dose. For this reason, a loading dose of 40 mg/kg via drinking water has been recently proposed for disodium fosfomycin versus E. coli strains, followed by ad libitum administration of 40 mg/kg 8h later (i.e. 80 mg/kg per day).

Internacionalización del proceso productivo: Una reseña sobre la literatura especializada Lucanera, Romina Anahí; González, Germán Héctor El fenómeno de la globalización, apoyado por el desarrollo tecnológico y constantes procesos de integración al mundo de multitud de países, ha generando un entorno económico y empresarial más complejo que lleva a considerar la internacionalización como una estrategia factible. Se presenta una reseña de la literatura especializada y comentarios referidos a la necesidad de amplificar los esfuerzos en el estudio de las experiencias de internacionalización en América Latina y el Caribe.; The globalization phenomenon together with the technological development and the permanent integration process of a multitude of countries, have generated a more complex management environment where de internationalization is a feasible strategy We present a review of the literature and some comments about the need to amplify the efforts in the study of the internalization process of the firm in Latin America and the Caribbean.

Organochlorine compound residues in the eggs of broad-snouted caimans (Caiman latirostris) and correlation with measures of reproductive performance Stoker, Cora; Repetti, María Rosa; García, S.R.; Zayas, Marcelo Alejandro; Galoppo, Germán Hugo; Beldoménico, H.R; Luque, Enrique Hugo; Muñoz de Toro, Monica Milagros Organochlorine compounds (OCCs), like pesticides (OCPs) and polychlorinated biphenyls (PCBs), are persistent lipophilic chemicals classified as endocrine-disruptors. Caiman latirostris inhabits wetlands throughout north-eastern Argentina and may accumulate OCCs. The aims of this study were to determine OCC residues in the eggs of C. latirostris and to correlate OCC burden with clutch size, hatching success and hatchling survival as measures of reproductive performance. Fourteen caiman clutches were harvested from sites with different degrees of anthropogenic intervention on wetlands surrounding Paraná River tributaries. Two to four eggs by clutch were used to quantify OCCs. OCP residues were found in all clutches. The principal contributors to the OCPs burden were the DDT family (range BDL-153.0ngg-1 lipid) and oxychlordane (range BDL-34.3ngg-1 lipid). PCBs were present in 92.9% of the clutches (range BDL-136.6ngg-1 lipid). Both higher concentrations and higher diversity of pesticides, including endosulfan sulfate, were found in the nests harvested close to croplands. A negative correlation was found between clutch size and ∑OCCs (p=0.02, Pearson r=-0.53, r2=0.28), mainly due to the ∑OCPs (p=0.04, Pearson r=-0.54, r2=0.30). Since egg OCCs concentrations predict maternal burden, present findings suggest that higher OCCs exposure could lead to smaller clutches. Although, other factors like mother age could influence clutch size. Additionally, as caimans are a long-lived and non-migratory species, the maternal OCCs burden reflects the environmental status throughout their home range; thus, caiman eggs could be useful as a biomonitor of local contamination.

Catalytic Degradation of Polystyrene: Modeling of Molecular Weight Distribution Gianoglio Pantano, Ioana Agustina; Asteasuain, Mariano; Diaz, Monica Fatima; Sarmoria, Claudia; Brandolin, Adriana Two of the most abundant polymers in household waste streams, PS and PE, may be recycled by compatibilization through a Friedel-Crafts alkylation. This reaction produces a graft copolymer PE-g-PS that improves the properties of the blend, but simultaneously degrades PS chains. Since the copolymer efficiency as a compatibilizer depends both on the molecular weight and MWD of its two blocks, the operating conditions for the copolymer synthesis must be carefully tuned. To aid in this task, we present a preliminary mathematical model that focuses on the effect of the catalyst and cocatalyst of the Friedel-Crafts alkylation on the MWD of the PS chains. The model's predictions are shown to agree with experimental data. The evolution of the complete MWD of PS subjected to Friedel-Crafts alkylation during reactive processing of thermoplastics from waste streams is modeled. This is the first step towards the development of a complete description of the graft reaction that will aid in the tuning of appropriate processing conditions.

Characterizing Trichoptera trophic structure in rivers under contrasting land use in Patagonia, Argentina Brand, Cecilia; Miserendino, Maria Laura Trichoptera is a widely distributed and diversified group in Andean Patagonia (Subandean Patagonic Province). This group exhibits a wide array of functional adaptations to exploit the available food resources. It is well known that changes in the relative abundance of functional-feeding groups (FFG) occur when the distribution of energetic resources (organic matter) is altered. In order to determine the functional structure variation among rivers subjected to different land uses, we selected 3 disturbance types (exotic plantation, pasture and logging) and native forest as reference. Three sites were assessed for each land use type (n=12) seasonally (every 3 months) and 6 samples with a Surber net (0.09 m-2 and 250 pore size) were taken. Larvae obtained were identified to the lowest possible taxonomic level, counted and assigned to a FFG using available references, knowledge of feeding modes and analysis of gut contents. A total of 32 taxa were identified belonging to 11 families. Mean annual densities of Trichoptera varied between 131 and 4231 ind.m-2. Pasture sites showed significantly higher density than pine and native forest sites. Overall Trichoptera FFG species composition was: shredder (10), predator (9), scraper (6), collector-filterer (5), algal-piercer (1), and collector-gatherer (1). The scraper Mastigoptila sp. was abundant in native forest rivers. Predators presented high density in logged forest sites. Shredders (53–98%) dominated rivers having dense forest cover; Parasericostoma ovale (Schmid) and Myotrichia murina Schmid (Sericostomatidae) being the most abundantspecies. Collector-filterers, mostly Smicridea annulicornis (Blanchard) and S. frequens (Navás)(Hydropsychidae), were the dominant group in pastures (42-96%), probably due to an increase of transported seston. According to these results, Trichoptera communities can be used as an early warning tool to assess changes in disturbed headwater systems in Patagonia.

Monte Carlo simulation of spectrum changes in a photon beam due to a brass compensator Custidiano, Ernesto Ramon; Valenzuela, Mercedes Raquel; Dumont, J. L.; McDonnell, J.; Rodriguez Aguirre, Juan Manuel Monte Carlo simulations were used to study the changes in the incident spectrum when a poly-energetic photon beam passes through a static brass compensator. The simulated photon beam spectrum was evaluated by comparing it against the incident spectra. We also discriminated the changes in the transmitted spectrum produced by each of the microscopic processes. (i.e. Rayleigh scattering, photoelectric effect, Compton scattering, and pair production). The results show that the relevant process in the energy range considered is the Compton Effect, as expected for composite materials of intermediate atomic number and energy range considered.

Improved state-variable internal model based digital controller for three-phase PWM inverters that complies with the standard IEC 62040-3 Botterón, Fernando; Humberto Pinheiro This paper proposes an improved state-variable internal model based digital voltage controller suitable for three-phase PWM inverters with output transformer for medium and high power uninterruptible power supplies (UPS). The proposed controller is derived from the internal model principle using a state-variable approach in stationary alfa-beta frame. For the controller design an improved discrete-time model that uses the average of two samples in a switching period is proposed. In addition, this model takes into account the digital implementation time delay. With the proposed controller it is possible to obtain a high performance in both steady-state and load transients. Also, with the selected internal model, dc components resulting from the circuit implementation non-idealities are not amplified, avoiding transformer saturation. To validate the proposed digital controller and to demonstrate the steady-state and transient performance, experimental results from a 10kVA space vector modulated three-phase inverter, fully controlled by a DSP TMS320F241, are presented. In steady-state the UPS output voltages have very low total harmonic distortion (THD) for both balanced and unbalanced non-linear loads. The output voltage dynamic performance complies with the international Standard IEC 62040-3 Classification 1, which is the most severe limit making the three-phase PWM inverter suitable for most types of critical loads.

Socio-environmental conditions, intestinal parasitic infections and nutritional status in children from a suburban neighborhood of La Plata, Argentina Gamboa, María Inés; Navone, Graciela Teresa; Orden, Alicia Bibiana; Torres, María Fernanda; Castro, Luis Eduardo; Oyhenart, Evelia Edith We analyzed intestinal parasitic infections in children aged 1-12 years from a poor neighborhood in La Plata, Argentina, and determined the correlations with their nutritional status and socio-environmental conditions. We performed parasitological analyses with anal brushed technique (for Enterobius vermicularis eggs) and fecal samples, employing the techniques of Ritchie, Carles Barthelemy and Willis. The worm burdens of nematodes were estimated by means of Kato Katz technique. Low weight-for-age (underweight), height-for-age (stunting) and weight-for-height (wasting) were calculated based on the 5th centile of the WHO 2006 (children under 5) and CDC 2000 (older children and adolescents) growth references. We also analyzed samples of soil, water, and canine feces and surveyed other domestic and environmental data using structured questionnaires to each child's parents. To associate the parasitological, anthropometric and socio-environmental data, a categorical analysis of principal components (catPCA) was conducted. In the first axis of catPCA, the correlations among socio-environmental variables showed a gradient of " relative welfare" The eigenvectors showed the most influential variables in the analysis were promiscuity (0.0765), father's education (-0.741), crowding (0.727), wastewater disposal (-0.658), mother's education (-0.574), and flooding (-0.409). The 85% of children were parasitized and 79.6% polyparasitized. The 27.7% of children had deficit in some nutritional status indicator, being the stunting the most prevalent deficit (16.8%). There also found parasites in 42% of the dog feces, 53% of the soil samples, and non-pathogenic amoebae in the water samples. The SEV was mainly associated with geohelminths and stunting, especially among the poorest children. The study evidences that living conditions are variable within this population. Part of these variations could be linked to the differences in the extent to which parents are able to use their scant resources to influence their children's morbidity. Further studies need to be done from a qualitative approach.