Selectividad isotópica en la disociación multifotónica infrarroja de SiF4; Isotopic selectivity in the infrared multiple-photon dissociation of SiF4 Alcaraz, A. N.; Codnia, Jorge; Azcárate, María Laura Se estudió la selectividad isotópica de la DMFIR de SiF4 con distintas líneas de emisión de la banda de 9,4 μm de un láser de CO2 TEA. Se irradiaron mezclas de SiF4 e H2 con la línea 9P(36), cuasi-resonante con la frecuencia vibracional del modo ν3 de 28SiF4, y con líneas corridas hacia el rojo y el azul con respecto de ésta. La fracción disociada por pulso se determinó por espectrometría FTIR siguiendo la desaparición de la molécula precursora, SiF4, y la aparición del producto, SiF3H. Los factores de enriquecimiento 29,30α en el reactivo (SiF4) y 29,30β en el producto (SiF3H) se determinaron mediante espectrometría de masas.; The isotopic selectivity of the IRMPD of SiF4 following irradiation with different emission lines of the 9.4 μm band of a TEA CO2 laser has been studied. The 9P(36) line is quasi-resonant with the vibrational frequency of the ν3 mode of 28SiF4. Mixtures of SiF4 and H2 have been irradiated with the rotational lines 9P(32) - 9P(42). The fraction of molecules dissociated per pulse was determined by FTIR spectrometry following the disappearance of the working molecule, SiF4, and the appearance of the product, SiF3H. The enrichment factors both in the reactant (SiF4), 29,30α, and in the product (SiF3H), 29,30β, have been determined by mass spectrometry

PCR múltiple para la detección de los genes sea, seb, sec, sed y see de Staphylococcus aureus: Caracterización de aislamientos de origen alimentario; Multiplex PCR for the detection of sea, seb, sec, sed and see genes of Staphylococcus aureus: Characterization of isolates from food Manfredi, E.A.; Leotta, Gerardo Anibal; Rivas, M. La presencia de Staphylococcus aureus en los alimentos representa un riesgo potencial para la salud pública; sus enterotoxinas son el principal factor de virulencia. La detección de las enterotoxinas de S. aureus puede realizarse por ELISA, aunque sólo es posible detectar el pool de enterotoxinas SEA, SEB, SEC, SED y SEE. Los objetivos del presente trabajo fueron optimizar dos técnicas de PCR múltiple para la detección de los genes sea, seb, sec, sed y see de S. aureus y caracterizar un conjunto de 115 aislamientos de Staphylococcus spp. asociados a intoxicaciones alimentarias provenientes de diferentes provincias de Argentina. La caracterización se realizó por pruebas bioquímicas, ELISA y PCR. Sesenta y ocho aislamientos (59,1%) fueron positivos por ELISA, mientras que 61 (53%) fueron positivos por PCR. De los aislamientos positivos por PCR, 34 (55,7%) portaron el gen sea, 9 (14,8%) el gen seb, 5 (8,1%) el gen see, 4 (6,5%) el gen sec, 6 (9,9%) los genes sea y seb, 2 (3,3%) los genes sea y sec, y 1 (1,7%) los genes sea y sed. Este es el primer estudio de caracterización genotípica de aislamientos de S. aureus asociados con brotes de intoxicación alimentaria registrados en distintas provincias argentinas.; The presence of Staphylococcus aureus in food represents a potential risk to public health, being its enterotoxins the major virulence factor. Enterotoxin detection can be determined by ELISA, but only for the pool of enterotoxins SEA, SEB, SEC, SED and SEE. The main aims of this study were to optimize two PCR techniques for detection of S. aureus sea, seb, sec, sed and see, and to characterize Staphylococcus spp. isolates associated with food intoxication. Two PCR techniques were optimized and 115 Staphylococcus spp. isolates from Ciudad Autónoma de Buenos Aires, and Buenos Aires, Córdoba, and Neuquén provinces were characterized. The characterization was performed by biochemical tests, ELISA and PCR. Sixty-eight isolates (59.1%) were positive by ELISA, while 61 (53%) were positive by PCR. Out of the positive PCR isolates, 34 (55.7%) carried the sea gene, 9 (14.8%) the seb gene, 5 (8.1%) the see gene, 4 (6.5%) the sec gene, 6 (9.9%) were positive for sea and seb genes, 2 (3.3%) for sea and sec genes, and 1 (1.7%) for sea and sed genes. This is the first study of genotypic characterization of S. aureus isolates associated with food intoxication from different provinces of Argentina.

Human papillomavirus DNA and oncogene alterations in colorectal tumors Perez, Luis Orlando; Barbisan, Gisela; Ottino, Anabel; Pianzola, Horacio; Golijow, Carlos Daniel The aim of the present study is to determine the presence and molecular integrity of high-risk HPV types in colorectal adenocarcinomas and to assess whether viral DNA is related to common proto-oncogene alterations, such as k-ras mutations and c-myc gene amplification, in colorectal cancer. Seventy-five colorectal adenocarcinomas were screened for HPV infection using nested-PCR (MY09/11-GP5+/6+). HPV typing was performed by type-specific PCR for HPV 16 and HPV 18 DNA. Unidentified samples were subsequently sequenced to determine the viral genotype. The physical status of HPV was determined by a nested PCR approach for type-specific E2 sequences. C-myc amplification was assessed by co-amplification with β-globin as control locus, and mutation in k-ras codons 12 and 13 by ARMS-PCR. Overall, HPV was detected in thirty-three colorectal specimens (44%). HPV 16 was the prevalent type (16/75), followed by HPV 18 (15/75), HPV 31 (1/75) and HPV 66 (1/75). E2 disruption was detected in 56.3% of HPV 16 and in 40% of HPV 18 positive tumors. C-myc amplification was detected in 29.4% of cases, while k-ras mutations in 30.7%. There was no significant trend for HPV infection in tumors harboring either k-ras or c-myc alterations. This study demonstrates HPV DNA and viral integration in colorectal tumors, suggesting a potential role of this virus in colorectal carcinogenesis. There was no concurrence, however, of k-ras and c-myc activation with viral infection.

La valoración del patrimonio desaparecido, un acercamiento a la cultura local desde el relato de los actores: El caso de la Estación Cerri en el partido de Bahía Blanca (Provincia de Buenos Aires); A valorização do patrimônio desaparecido, uma aproximação com a cultura local a partir do relato dos atores: O caso da Estação Cerri no distrito de Bahía Blanca (Província de Buenos Aires); Valorization of lost patrimony, an approach to local culture from the narratives of social actors: The case of the ‘Cerri Railway Station’ in the district of Bahía Blanca (Province of Buenos Aires) Kraser, María Belén; Lorda, María Amalia Desde la visión de la Geografía Social y Cultural del espacio como identidad, de lugar vivido, los espacios se cargan de sentimientos que sólo pueden ser comprendidos desde el relato, la historia y las imágenes de los propios actores locales involucrados. Ambas reivindican la compresión frente a la explicación y valoran la emoción por encima del objeto material de los fenómenos sociales (Comerci, 2005). La identidad de los espacios implica el reconocimiento del patrimonio local, que involucra al conjunto de manifestaciones materiales e inmateriales que una sociedad carga de valor y significado conformando su cultura local. Tanto el patrimonio visible como el invisible, sustentado como parte constituyente del imaginario social y alimentado por historias e imágenes, merecen especial atención, puesto que al evaluar un patrimonio se adopta también un fundamento ético con el cual se sustenta una posición responsable (Lorda, 1998). En algunas oportunidades el reconocimiento de un componente tangible local como parte integrante del patrimonio de una comunidad, deviene con la desaparición del mismo, puesto que la valoración y sentimiento de pertenencia se evidencian cuando por distintos motivos ya no están. Este es el caso de la primigenia estación férrea de la localidad de General Daniel Cerri, poblado situado a 15km de la ciudad de Bahía Blanca en el partido homónimo, al sudoeste de la provincia de Buenos Aires. El valor histórico cultural de la misma en el área radica en su vinculación al desarrollo del poblado en tiempos pasados y en relación directa con el devenir económico y social del país desde fi nes de siglo XIX; aspecto que hoy debe ser abordado mediante la línea de análisis del patrimonio desaparecido. La metodología empleada de carácter cualitativo permite el predominio del trabajo de campo en ente escrito, mediante la recopilación de información por medio de observaciones y entrevistas semiestructuradas a informantes claves. La técnica de biografías individuales desde la mirada microsocial en conexión con la temporalidad espacial se convierte en pilar esencial, enmarcada a su vez en base a la recopilación, análisis e interpretación de bibliografía pertinente que brindan el encuadre teórico.; Sob o ponto de vista da Geografi a Social e Cultural do espaço como identidade, de lugar vivido, os espaços se carregam de sentimentos que só podem ser compreendidos pelo relato, a história e as imagens dos próprios atores locais envolvidos. Ambas reivindicam a compreensão frente à explicação e valorizam a emoção em detrimento do objeto material dos fenômenos sociais (Comerci, 2005). A identidade dos espaços implica o reconhecimento do patrimônio local, que envolve o conjunto de manifestações materiais e imateriais que uma sociedade carrega de valor e signifi cado conformando sua cultura local. Tanto o patrimônio visível como o invisível, sustentado como parte constituinte do imaginário social e alimentado por histórias e imagens, merecem especial atenção, posto que ao avaliar um patrimônio se adote também um fundamento ético com o qual se sustenta uma posição responsável (Lorda, 1998). Em algumas oportunidades o reconhecimento de um componente tangível local como parte integrante do patrimônio de uma comunidade, surge com o desaparecimento do mesmo, posto que a valorização e sentimento de pertencimento se evidenciam quando por distintos motivos já não estão lá. Este é o caso da primeira estação férrea da localidade de General Daniel Cerri, povoado situado a 15km da cidade de Bahía Blanca no distrito homônimo, ao sudoeste da província de Buenos Aires. O valor histórico e cultural da mesma na área se radica em sua vinculação ao desenvolvimento do povoado em tempos passados e em relação direta com o devir econômico e social do país desde fi ns do século XIX; aspecto que hoje deve ser abordado mediante a linha de análise do patrimônio desaparecido. A metodologia empregada de caráter qualitativo permite o predomínio do trabalho de campo, mediante a recopilação de informação por meio de observações e entrevistas semi-estruturadas a informantes chave. A técnica de biografi as individuais sob o olhar microsocial em conexão com a temporalidade espacial se converte em pilar essencial, enquadrada por sua vez com base na recopilação, análise e interpretação de bibliografi a pertinente que brindam o quadro teórico.; From the vision of Social and Cultural Geography, of space as identity, as lived space, spaces are loaded with feelings which can olny be understood from the narratives, stories and images of local actors. Both disciplines remark the importance of understanding over explaining and value emotion over the material object of the social phenomena (Comerci, 2005). The identity of spaces implies the recognition of the local patrimony that invloves material and immaterial manifestations that a society loads with value and meaning to conform its local culture. The visible and invisible patrimony considered as part of the social imaginary and built on the basis of stories and images, deserve special attention because, to evaluate patrimony, implies adopting an ethical basis from a responsible position (Lorda, 1998). On occassions, the recognition of a local and tangible component as part of the patrimony in a comunity begins with the disappearance of that component, since its valorization and sense of belonging become evident when it no longer exists or has been lost. This is the case of the original railway station of the town of General Cerri, located 15 km from the city of Bahía Blanca, to the Southwest of the province of Buenos Aires. The historical and cultural value of this station in the area is related to the development of the town in the past and to the socio-economical evolution of the country during the XIX century, a fact that today needs to be approached from the perspective of lost patrimony. The qualitative methodology used allows for the predominance of fi eld work turned into written versions and data collection through observation and semiestructural interviews to key informants. The technique of individual biographies analysed from a microsocial perspective in conection with the spatial temporality is essential and at the same time becomes the basis for the collection, analysis and interpretation of the appropriate bibliography which provides the theoretical framework.

Phytochemical variability of populations of Aloysia citriodora from Argentina Di Leo Lira, Paola Maria del Rosario; Retta, Daiana Sabrina; Van Baren, Catalina Maria; Gorzalczany, Susana Beatriz; Bandoni, Arnaldo Luis Aloysia citriodora Palau (Verbenaceae) is one of the most widely used herbs in the Argentine traditional medicine as antispasmodic, sedative and for the treatment of stomachache. Its worldwide use has promoted its cultivation not only in our country but also in several Latin American countries, Europe and Asia. There are official monographs in Argentine (FA) and European Pharmacopoeias (PhEU, as „lemon verbena) for the pharmaceutical quality control. Our working group is devoted to update the respective monograph of the FA, taking in account the detected phytochemical variability of local populations. Parameters for a quality profile of volatile metabolites were previously established [1,2]. At this time we have evaluated the phytochemical variability of several populations using the technique by the European Pharmacopoeia (HPLC), in order to identify the best materials for crops affordable for the pharmaceutical industry. We analyzed 22 populations from 12 regions from Argentina, both in culture and wild materials. Our results show significant differences in the contents of verbascoside: from 0.5 to 4.8%, being 2.5% the minimum accepted value in the PhEu. Other peaks were detected in the HPLC profiles, some of them with similar UV spectra as verbascoside, meanwhile others with polyphenolic UV pattern. Therefore, in vitro assays will be undertaken to determine if the quantity of verbascoside itself affects proportionally the pharmacological activity

Efectos de la estructura productiva desequilibrada y de los esquemas cambiarios sobre el ciclo del empleo en la Argentina; Effects of productive heterogeneity and different exchange rate schemes on the employment cycle in Argentina Panigo, Demian Tupac; Chena, Pablo Ignacio; Gárriz, Ana Inés El objetivo central del presente artículo consiste en examinar los efectos de los esquemas cambiarios, los regímenes de demanda y la estructura productiva sobre la volatilidad cíclica del empleo en Argentina durante las últimas dos décadas. El principal aporte de la investigación radica en el desarrollo teórico de una serie de modelos dinámicos que se nutren de distintas escuelas de pensamiento heterodoxas (según la definición de Foley y Taylor, 2004), para dar cuenta de las características cíclicas del empleo que resultan de combinar la estructura productiva desequilibrada con el acelerador de la inversión, el multiplicador keynesiano, las pujas distributivas, y los canales de ajuste de economía abierta (comercial y financiero).; The aim of this paper is to examine the effect of different exchange rate schemes, alternative demand regimes and variable degrees of productive heterogeneity on employment volatility in Argentina over the last two decades. The main contribution lies in the theoretical development of a series of dynamic simultaneous equation models owing to different heterodox schools of thought (following the definition given by Foley and Taylor, 2004), to show the cyclical characteristics of employment that result from combining an unbalanced economic structure with the investment accelerator, the Keynesian multiplier, the class struggle and the open economy adjustment channels (financial and commercial).

A new species and variety of Senecio (Asteraceae) from Patagonian Argentina Tortosa, Roberto Daniel; Bartoli, Adriana Two novelties in the genus Senecio L. sect. Senecio of Patagonia (Argentina) are described and illustrated: a new species, S. breviramulus Tortosa & Adr. Bartoli belonging to series Xerosenecio (Cabrera) Cabrera & S. E. Freire, and the new variety pinohachense Tortosa & Adr. Bartoli for S. volckmannii Phil. belonging to series Suffruticosi Cabrera subser. Candidi (Cabrera) Cabrera & S. E. Freire. The new species is allied to S. covasii Cabrera and S. pumilus Tortosa & Adr. Bartoli, from which it differs by the smaller, narrowly elliptic leaves and narrower heads with fewer flowers. The new variety of S. volckmannii differs from the typical variety by the presence of female ray florets and the pedunculate capitula.; Se describen e ilustran dos novedades en el género Senecio L. sect. Senecio de Patagonia (Argentina): una nueva especie S. breviramulus Tortosa & Adr. Bartoli, que pertenece a la serie Xerosenecio (Cabrera) Cabrera & S. E. Freire, y una nueva variedad, S. volckmannii Phil. var. pinohachense Tortosa & Adr. Bartoli, de la serie Suffruticosi Cabrera subser. Candidi (Cabrera) Cabrera & S. E. Freire. La nueva especie es afín a S. covasii Cabrera y S. pumilus Tortosa & Adr. Bartoli, de las cuales se diferencia por sus hojas menores, angostamente elípticas, y sus capítulos más angostos, con menor número de flores. La nueva variedad de S. volckmannii se diferencia de la variedad típica por la presencia de flores liguladas femeninas y capítulos pedunculados.

Study of the adsorption, electronic structure and bonding of C2H4 on the FeNi(1 1 1) surface Simonetti, Sandra Isabel; Brizuela, Graciela Petra; Juan, Alfredo The adsorption of C2H4 on the FeNi(1 1 1) alloy surface has been studied by ASED-MO tight binding calculations. The C2H4 molecule presents its most stable geometry with the C{double bond, long}C bond axis parallel to the surface along the [1, -1, 0] direction, bonded on top Fe atom and bonded along a Fe-Fe bridge site. As a consequence, the strength of the local Fe-Fe bond decreases between 37 and 62% of its original bulk value. This bond weakening is mainly due to the new C-Fe interactions however no Fe3C carbide formation is evidenced on surface. The Fe-Ni and Ni-Ni superficial bonds are only slightly modified.

Electrochemical Study of the Antioxidant Activity and the Synergic Effect of Selenium with Natural and Synthetic Antioxidants Bertolino, Franco Adrián; Stege, Patricia Wanda; Salinas, Eloy; Messina, Germán Alejandro; Raba, Julio In this paper we propose two different electrochemical methods such as Cyclic Voltammetry (CV) and Osteryoung Square Wave Voltammetry (OSWV) to study the free radical scavenging ability of Selenium (Se) and natural and synthetic antioxidants. The originality of this paper is based on the study of the synergic effect of Se, not only with a-Tocopherol, but with a variety of antioxidants. As a result, we find an important synergism, in vitro, between Se and some other natural and synthetic antioxidants in the aqueous medium.

A simple model for the evolution of multi-stranded coronal loops Lopez Fuentes, Marcelo Claudio; Klimchuk, J. A. We develop and analyze a simple cellular automaton model that reproduces the main properties of the evolution of soft X-ray coronal loops. We are motivated by the observation that these loops evolve in three distinguishable phases that suggest the development, maintenance, and decay of a self-organized system. The model is based on the idea that loops are made of elemental strands that are heated by the relaxation of magnetic stress in the form of nanoflares. In this vision, usually called the “Parker conjecture,” the origin of stress is the displacement of the strand footpoints due to photospheric convective motions. Modeling the response and evolution of the plasma we obtain synthetic light curves that have the same characteristic properties (intensity, fluctuations, and timescales) as the observed cases. We study the dependence of these properties on the model parameters and find scaling laws that can be used as observational predictions of the model. We discuss the implications of our results for the interpretation of recent loop observations in different wavelengths.

Teología política y política postmetafísica Torres Castaños, Sebastián En 1922, Carl Schmitt publica Teología política, breve texto de compleja composición que contiene dos líneas provocadoras; la primera línea del capítulo I: "Es soberano quien decide el estado de excepción"; la otra, primera' línea del capítulo m: "Todos los conceptos significativos de la moderna teoría del Estado son conceptos teológicos secularízados'". La relación entre las dos partes de la obra (caps. I-TI y caps. m-IV) no es de por si evidente. En la primera parte presenta una argumentación lógicojurídica que parece sostenerse con total autonomía de cualquier recurso teológico. En un tiempo dominado por el renacimiento del "mito" (de los Nibelungos a Sorel), la comprensión de la intención schmittiana tenía amplias posibilidades de caer en el vacío de la retórica demagógica, del romanticismo nacionalista o del irracionalismo catártico de la crisis europea. Carl Schmitt es, si embargo, el paradigma de la restitución moderna de una "teología política secular".

Innovation and productivity in the Argentine manufacturing sector Arza, Valeria; Lopez, Andres Flavio This paper adapts the Crepon, Duguet, and Mairesse (1998) approach to estimate the relationship between innovation and productivity and the realities of innovative activities in developing countries. Panel data for Argentina during the period 1998-2004 to estimate a structural model in which different types of firms’ innovative behavior—including in-house activities and the incorporation of external technologies—feeds into the probability of achieving successful results in product and process innovation, which in turn explains labor productivity. The endogeneity of this three-stage process is controlled for. The results suggest that all types of innovative activities are relevant to explain success in product and process innovation, and both are important factors to explain labor productivity. Moreover, investing systematically in R&D implies an extra payoff in labor productivity. These results suggest that investing in different types of innovative activities—and not only in R&D—and doing in-house activities systematically contribute to firms’ innovative and economic performance

Review of the sarcophaginae (Diptera: Sarcophagidae) of Buenos Aires province (Argentina), with a key and description of a new species Mulieri, Pablo Ricardo; Mariluis, Juan Carlos; Patitucci, Luciano Damián Thirty-nine species of Sarcophaginae are recorded from Buenos Aires Province (Argentina). A new species, Microcerella asymmetrica sp. nov., is described. Females of Oxysarcodexia bicolor Lopes, O. marina Hall, and Sarcophaga (Lipoptilocnema) koehleri Blanchard are described for the first time. Four nomenclatorial actions are reported: Sarcohelicobia elegans Blanchard is established as a new junior synonym of Nephochaetopteryx cyaneiventrisLopes, and lectotypes are designated for Oxysarcodexia delpontei Blanchard [a junior synonym of Oxysarcodexia paulistanensis (Mattos)], Sarcophaga argentina Brèthes [a junior synonym of Sarcophaga (Liopygia) argyrostoma(Robineau- Desvoidy)], and Neobellieria brethesi Blanchard [a junior synonym of Sarcophaga (Neobellieria) polistensisHall]. Blaesoxipha (Tephromyia) hospes (Aldrich), Peckia (Euboettcheria) florencioi (Prado & Fonseca), Raviniaadvena (Walker), R. aureopyga (Hall) and Sarcodexia lambens (Wiedemann) are newly recorded from Buenos Aires Province, and Udamopyga percita is newly recorded from Argentina. A key is presented to the adult males and females of 36 of the 39 species of Sarcophaginae recorded from Buenos Aires province. Notes on distribution, biology, life history and host records are also given.

Jacobi contra Fichte, el Mesías de la razón pura Sole, Maria Jimena This article deals with F. H. Jacobi´s criticism of Fichte´s thought, just as it is exposed it in his Briefe an Fichte, of 1799. In order to offer the context of the discussion between them, we analyze, in the first place, the connection that existed between both philosophers before the Atheismusstreit. Then, we expose Jacobi´s interpretation of the Wissenschaftslehre as the most accomplished system in the history of rationalist philosophy -for which Fichte is designated as the Messiah of speculative reason. To conclude, we analyze briefly Fichte?s reaction to these criticisms.  The article shows that, just as Fichte claims and contrary to what Jacobi affirms, there are some coincidences between them concerning their philosophical views. They agree, among others things, in their appraisal of Spinozism; but fundamentally they concur in that they both dethrone speculative reason and set above it a not demonstrative, not discursive power that can be in both cases considered as nicht-Wissen.

El movimiento estudiantil reformista frente al primer episodio de la Laica o Libre (mayo de 1956) Califa, Juan Sebastián En mayo de 1956 se libró en la Argentina el primer episodio del conflicto "Laica o Libre". Así se llamó al enfrentamiento entre reformistas, contrarios al artículo 28 del decreto-ley 6.403 que permitía a las universidades privadas otorgar títulos habilitantes, y católicos favorables al mismo. En este contexto, se registró un ascendente proceso de tomas estudiantiles de secundarios y universidades. El conflicto le costó el cargo al católico ministro de Educación nacional Atilio Dell Oro Maini y a los rectores de las universidades de Buenos Aires (UBA) y de Córdoba (UNC). No obstante las tensas implicancias que el mismo deparó dentro del gobierno de la autoproclamada "Revolución Libertadora", poco se conoce sobre él. En este artículo iniciaré su estudio. Para ello reconstruiré los hechos a través de los diarios La Nación y La Prensa, entre otras fuentes y bibliografía. Particularmente concentraré mi atención en el estudiantado reformista de la UBA.

Adsorption properties in high optical quality nanoZIF-8 thin films with tunable thickness Demessence, Aude; Boissière, Cédric; Grosso, David; Horcajada, Patricia; Serre, Christian; Férey, Gérard; Soler Illia, Galo Juan de Avila Arturo; Sanchez, Clément We report processing of a thin film by chemical solution deposition of a microporous ZIF-8 nanoparticle dispersion. By using the drain and capillary regimes involved in the dip-coating process, we tuned the thickness of the films from 40 nm to 1 µm and controlled the packing of the nanoparticles on the substrate. The high optical quality thin films show a dual hierarchical porous structure from the micropores of the framework and the mesoporous interparticular voids. Moreover, vapor sorption properties of the microporous ZIF-8 based thin films have been evaluated by ellipsometric porosimetry. The hydrophobic films show alcohol, THF and hydrocarbon adsorption. Experiments for isopropanol/water separation have been carried out and the selective adsorption of the alcohol versus the water makes these thin films good candidates for vapor sensors.

Escenarios sociales y participación política juvenil: un repaso de los estudios sobre comportamientos políticos desde la transición democrática hasta Cromagnon Nuñez, Pedro Fernando Este trabajo busca explorar el modo en que las ciencias sociales analizaron en los últimos tiempos los procesos sociales que afectaron a la juventud. La intención es incorporar nuevas claves de lectura de los fenómenos contemporáneos, que permitan intuir los modos de involucrarse en la sociedad protagonizados por los jóvenes. En los primeros apartados se analiza brevemente las perspectivas predominantes con las que las ciencias sociales en general, y los estudios sobre juventud en particular, indagaron en la relación de las nuevas generaciones con la política desde el regreso a la vida democrática en 1983. En un segundo momento, realizamos el ejercicio comparativo de pensar el impacto que tuvieron dos sucesos de amplia repercusión (el incendio ocurrido en Cromagnon y los hechos violentos que acontecieron en una escuela en Carmen de Patagones) en las prácticas y acciones políticas de los y las jóvenes que asisten a establecimientos educativos de nivel secundario en dos jurisdicciones del sistema educativo.

What shapes edaphic communities in mineral and ornithogenic soils of Cierva Point, Antarctic Peninsula? Mataloni, Maria Gabriela; Gonzalez Garraza, Gabriela Carolina; Bölter, Manfred; Convey, Peter; Fermani, Paulina Three mineral soil and four ornithogenic soil sites were sampled during summer 2006 at Cierva Point (Antarctic Peninsula) to study their bacterial, microalgal and faunal communities in relation to abiotic and biotic features. Soil moisture, pH, conductivity, organic matter and nutrient contents were consistently lower and more homogeneous in mineral soils. Ornithogenic soils supported larger and more variable bacterial abundances than mineral ones. Algal communities from mineral soils were more diverse than those from ornithogenic soils, although chlorophyll- a concentrations were significantly higher in the latter. This parameter and bacterial abundance were correlated with nutrient and organic matter contents. The meiofauna obtained from mineral soils was homogeneous, with one nematode species dominating all samples. The fauna of ornithogenic soils varied widely in composition and abundance. Tardigrades and rotifers dominated the meiofauna at eutrophic O2, where they supported a large population of the predatory nematode Coomansus gerlachei. At site O3, high bacterial abundance was consistent with high densities of the bacterivorous nematodes Plectus spp.This study provides evidence that Antarctic soils are complex and diverse systems, and suggests that biotic interactions (e.g. competition and predation) may have a stronger and more direct influence on community variability in space and time than previously thought.

Conflictos territoriales en ámbitos rurales de la Argentina actual Manzanal, Mabel Adelaida; Arzeno, Mariana Beatriz En el ámbito rural en Argentina se percibe, desde la década de 1990, un aumento de la conflictividad social. Surgen localmente movimientos, conflictos y demandas vinculadas con la apropiación y uso de los recursos del territorio (tierra, agua, minerales, bosques, infraestructura, etc.) o con las consecuencias ambientales del accionar del hombre sobre el mismo (contaminación, deforestación, inundaciones). Sin embargo, y a pesar que muchos de ellos han tomado estado público, estos conflictos en su mayoría se ignoran o se minimizan. Sin embargo, otra trascendencia tuvo el que se desencadenó en marzo de 2008, conocido como el conflicto “del campo” o “agrario”. Este conflicto estuvo atravesado por múltiples contradicciones, discrepancias y confusiones promovidas por ambos sectores en pugna (referentes del sector agrario y gobierno). Y lejos de representar una problemática universal del “campo”, no fue más que la expresión de una disputa al interior de los sectores dominantes. En este trabajo, a partir de estudios de caso en las provincias de Salta y Misiones, aplicando metodologías cualitativas y desde una perspectiva analítica que visualiza los conflictos como expresiones de luchas de poder por los recursos del territorio, nos proponemos mostrar las contradicciones y consecuencias territoriales de conflictos asociados tanto con disputas por el poder hegemónico como los vinculados con resistencias al modelo de desarrollo dominante y excluyente.; No âmbito rural na Argentina percebe-se, desde a década de 1990, um aumento dos conflitos sociais. Surgem localmente movimentos, lutas e demandas vinculadas com a apropriação e uso dos recursos do território (terra, água, minerais, bosques, infraestrutura, etc.) ou com as consequências ambientais da ação do homem sobre o mesmo (contaminação, desmatamento, inundações). Todavia, e apesar de muitos deles terem se tornado públicos, esses conflitos em sua maioria são ignorados ou se minimizam. Entretanto, o que se desencadeou em março de 2008, conhecido como o conflito do campo ou agrário, teve outra transcendência. Este conflito foi atravessado por múltiplas contradições, discrepâncias e confusões promovidas por ambos os setores em luta (referentes do setor agrário e governo). E longe de representar uma problemática universal do campo, não foi mais do que a expressão de uma disputa no interior dos setores dominantes. Neste trabalho, a partir de estudos de caso nas províncias de Salta e Misiones, aplicando metodologias qualitativas e a partir de uma perspectiva analítica que visualiza os conflitos como expressões de lutas de poder pelos recursos do território, propomos mostrar as contradições e consequências territoriais dos conflitos associados tanto às disputas pelo poder hegemônico como os vinculados a resistências ao modelo de desenvolvimento dominante e excludente.

Genealogía de la semilla: Regulación y escasez en la Región Pampeana argentina Hendel, Verónica Hacia fines del año 2001, los términos “hambre” y “Argentina” comenzaron a ser sinónimos de la crisis del neoliberalismo. La inquietud que guía este trabajo es la pregunta por la especificidad de ese peligro del hambre que sigue resonando entre nosotros. Un peligro que se enlaza con otros y que sólo a partir de ese vínculo, ese entramado, puede ser comprendido en su complejidad. Es en este sentido, que el hambre, la agricultura y el crecimiento demográfico se amalgaman y sus contornos se tornan difusos hasta desdibujarse. Este es uno de los motivos por los cuales, además del hecho de que no nos interesa analizar el fenómeno tal como se expresa en el mercado, hemos elegido un sendero que yace al interior de este dispositivo de saber-poder y que se transformará en nuestra guía: la semilla. Es decir, esa fuente de potencia nutritiva, depósito de la vida y punto de partida del alimento. Entonces, a lo largo de este artículo analizaremos el problema del hambre como escasez, en su doble dimensión agricultura/crecimiento demográfico, a partir de las múltiples intervenciones que en el caso de la Argentina, especialmente a partir de la década de 1930, han emergido a fin de regular la producción, el uso y la circulación de semillas en la Región Pampeana.; Towards the end of the year 2001, the terms hunger and Argentina became synonyms of the crisis of neoliberalism. This article examines the specificity of that danger of hunger that emerges from time to time, and continuous resounding among us. A danger that connects with others and that only by considering those links, that web, we may understand in deep. It is in this sense that hunger, agriculture and population growth amalgam and their boundaries turn vague until they blur. This is one of the reasons why, apart from the fact that we are not interested in analyzing the phenomenon as it may appear in the market, we have chosen a path that lies inside this knowledge-power apparatus (dispositif) and that will become our guide: the seed; that is to say, the source of nutritious potential, life deposit, and food starting point. So, along this article we shall deal with the problem of hunger as scarcity, in its double dimension agriculture/population growth, from the multiple interventions that in Argentina’s case, especially since the 1930s, have emerged in order to deal with the production, use and circulation of seeds in the Pampas Region.