Estudio de la distribución del antibiótico fosfomicina en calostro-leche de cerdas; Study of the distribution of fosfomycin antibiotic in sows colostrum Fernández Paggi, María Belén; Soraci, Alejandro Luis; Tapia, Maria Ofelia; Amanto, Andres Fabian El uso de antibióticos (ATB) por vía sistémica en cerdas en producción durante el peri-parto es una práctica frecuente y poco racional, la cual se realiza con el objetivo de “disminuir la carga bacteriana” a la cual van a ser sometidos los lechones neonatos. No existe en la bibliografía estudios sobre la distribución de ATB en calostro o leche de cerda. El objetivo del trabajo fue estudiar la distribución del ATB fosfomicina disódica (FOS) en calostro y leche de cerda. FOS fue analizada por HPLC MS-MS. Las concentraciones de FOS tuvieron un rango máximo y mínimo de 1,60 ± 0,89 y 0,34 ± 0,16 μg/ml respectivamente. El consumo promedio de fosfomicina de la camada fue de 0,27 mg/kg equivalente a 1,35 % de la dosis terapéutica oral de fosfomicina en cerdos. El porcentaje promedio de dosis de fosfomicina eliminada por calostro fue de 1,8 %. Dicho ATB podría ser utilizado en la cerda durante el parto-lactancia con cierta seguridad para el lactante. No obstante, se debería analizar el verdadero impacto de las concentraciones de FOS obtenidas en calostro para determinar los efectos de la droga sobre la implantación de la microbiota intestinal del lechón lactante.; The use of antibiotics (ATB) in sows during peripartum is a common practice in commercial pig farms. The aim of this practice is to reduce the bacterial load at which the suckling piglet will be exposed at birth. In the bibliography, there are not any studies on the distribution of fosfomycin in colostrum and milk sow. In this work we focus on the study of the distribution of disodium-fosfomycin antibiotic in colostrum and milk sow. Fosfomycin (FOS) concentrations were analyzed by HPLC MS-MS method. Calostral concentration shows a range of 1.60 ± 0.89 and 0.34 ± 0.16 μg/ml between farrow and 10 h after the birth of the first piglet. The average consumption of litter fosfomycin was 0.27 mg/kg, equivalent to 1.35 % of the oral therapeutic dose in pigs. The percentage of IM dose of fosfomycin eliminated by colostrum was 1.8 %. Also, disodium-fosfomycin could be used during farrow-lactation in the sow with some safety measures for piglet suckling. However, the impact of the concentrations of FOS in colostrum should be analyzed to determine the effects of the drug on the intestinal microbiota implantation of the suckling piglet.

The Role of Oxygen- and Nitrogen-containing Surface Groups on the Sintering of Iron Nanoparticles on Carbon Nanotubes in Different Atmospheres Sanchez, Miguel Dario; Chen, Peirong; Reinecke, Thomas; Muhler, Martin; Xia, Wei The sintering of iron nanoparticles on carbon nanotubes (CNTs) under different atmospheres was investigated. CNTs were first treated with HNO3 vapor at 200 °C to obtain O-functionalized CNTs (OCNTs). The OCNTs were treated in ammonia at 400 °C to obtain N-doped CNTs (NCNTs). Highly dispersed FeOx nanoparticles were subsequently deposited by chemical vapor deposition from ferrocene under oxidizing conditions. The obtained FeOx/OCNT and FeOx/NCNT samples were allowed to sinter at 500 °C under flowing helium, hydrogen, or ammonia. The samples were studied by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. A significant increase in particle size and a decrease in Fe surface atomic concentration were observed in all the sintered samples. The sintering on OCNTs was more severe than on NCNTs, which can be attributed to stronger metal-substrate interactions and a higher amount of surface defects on NCNTs. The applied gas atmosphere had a substantial influence on the sintering behavior of the nanoparticles: treatment in helium led to the growth of particles and a significant widening of particle size distributions, whereas treatment in hydrogen or ammonia resulted in the growth of particles, but not in the widening of particle size distributions.

Evaluating tag filtering techniques for web resource classification in folksonomies Tourné, Nicolás; Godoy, Daniela Lis Social or collaborative tagging systems emerged as a novel classification scheme on the Web based on the collective knowledge of people. In sites such as Del.icio.us, Technorati or Flickr, users annotate a variety of resources, including Web pages, blogs, pictures, videos or bibliographic references; using freely chosen textual labels or tags. Underlying collaborative tagging systems are ternary data structures known as folksonomies relating resources and users through tags, this information facilitate accessing and browsing massive repositories of resources. Collective annotations provided by people in the form of tags can also be exploited to organize resources on-line in a more formal classification scheme such as the ones provided by hierarchies or directories, alleviating the task of manual classification commonly required by systems like directories on the Web. In this paper we present an empirical study carried out to determine the value of tags in resource classification. Furthermore, the use of several filtering and pre-processing operations to reduce the ambiguity and noise in tags are analyzed to determine whether they allow to increase the quality of resource classification.

Two new species of Emmallodera Blanchard, 1842 (Coleoptera: Tenebrionidae) from western Argentina Silvestro, Violeta Ayelen; Flores, Gustavo Ernesto Two new species of the genus Emmallodera Blanchard (Tenebrioninae: Scotobiini) from western Argentina are described, Emmallodera rugosa sp. nov. from the Patagonian steppe and Emmallodera telteca sp. nov. from lowlands in the Mendoza province. Distributional data, habitat records, and photographs of habitus and pronota for these two new species are included, with comparisons to other known species of the genus.

A new limnic species of Macrostomum (Platyhelminthes: Macrostomida) from Argentina and its muscle arrangement labeled with phalloidin Adami, Mariana Laura; Damborenea, Maria Cristina; Ronderos, Jorge Rafael A new species of Macrostomum from limnic environments in Argentina is described. Macrostomum platensis n. sp. differs from its congeners by the shape and length of its stylet. Moreover, the arrangement of the muscle system is described using rhodamine-labeled phalloidin. This method provides detailed information on the complex arrangement of muscles of the body wall, pharynx, head and reproductive organs. The resulting description is compared with previously published ones using the same methodological approach. The muscle arrangement may be considered for future taxonomic studies within the genus Macrostomum and might provide phylogenetically useful characters.

¿Desde dónde intervenimos cuando intervenimos? El caso del proyecto Tomate Platense; From where we intervene when we intervene? The case of the "Tomato Platense Project" Garat, Juan Jose; Otero, Jeremías Este trabajo se propone una reflexión crítica sobre una experiencia de intervención (El Proyecto Tomate Platense) en la que los autores de este artículo hemos participado desde su comienzo. Dicha reflexión implica poner en evidencia y en discusión, el qué y el cómo de la intervención para el desarrollo rural. Para esto, trabajamos los conceptos de: modelos de desarrollo e intervención, tecnología, hegemonía y agricultura familiar; y planteamos a su vez como estrategia metodológica, al estudio de caso. Posteriormente, realizamos una descripción del proceso de la intervención, identificando etapas y poniendo en relieve aspectos que consideramos significativos. En ese sentido visualizamos un proceso de legitimación de una propuesta alternativa, que implica en un sentido un quiebre del espiral tecnológico dominante presente en el cinturón hortícola de La Plata. La formulación inicial de la propuesta surge a partir de un diagnóstico de gabinete, realizado en el ámbito de la Facultad de Ciencias Agrarias y Forestales de la UNLP, que tiene un posterior devenir participativo que implica reformulaciones parciales y periódicas de la propuesta inicial.; This work proposes a critical thought on an intervention experience (the “tomato platense” project) in which the authors of this article have participated since its beginning. Such thought implies to put in evidence and discussion, the “what” and the “how” of the intervention for rural development. For this, we work the concepts of: models of development and intervention, technology, hegemony and family farming; and we propose at the same time, a case study methodological strategy. Subsequently, we carry out a description of the intervention process, identifying stages and highlighting aspects that we consider significant. In that regard we envision a process of legitimization of an alternative proposal, which means in a sense a break-up of the technology spiral dominant present in horticultural belt of La Plata. The initial formulation of the proposal arises from a diagnosis made in Cabinet, in the Faculty of Agricultural and Forest Sciences of the UNLP, which has a later participatory becoming, involving partial and periodic reformulation of the initial proposal.

Groundwater flow model, recharge estimation and sustainability in an arid region of Patagonia, Argentina Alvarez, Maria del Pilar; Trovatto, Maria Marta; Hernandez, Mario Alberto; Gonzalez, Nilda The Península Valdés, in northeastern Patagonia, Argentina, is characterised by its arid climate and the lack of perennial watercourses; thus, all economic activities depend on the groundwater resources. Water demand is mainly associated with tourism, which is centralised in Puerto Pirámides and supplied by a water desalination plant, and to sheep farming, supplied by the local aquifer. Due to the exponential growth of tourism, the government is planning to exploit groundwater and convey it by aqueduct to the abovementioned locality. The objectives of this study were to corroborate the conceptual geohydrological model, to develop a mathematical model to simulate the response of the aquifer to different scenarios, and to assess the incidence of water input into the system as a variable-a function that poses difficulties in the models for arid regions. The Visual Modflow 4. 1 code was used, calibrating it in trial-and-error mode, changing the recharge and hydraulic conductivity parameters with different variants in the recharge zone and in the inclusion or exclusion of the evapotranspiration module. Results indicate the importance of the recharge analysis by treating rainfall at daily time steps. The adjusted model was exposed to four scenarios with variations in water input and in output by pumping. It can be concluded that under different input conditions, but with a controlled extraction, the system responds in a sustainable manner. © 2011 Springer-Verlag.

Characterization of the M32 metallocarboxypeptidase of Trypanosoma brucei: Differences and similarities with its orthologue in Trypanosoma cruzi Frasch, Alejandra P.; Carmona, Raquel Adriana; Juliano, Luis; Cazzulo, Juan Jose; Niemirowicz, Gabriela Teresa Metallocarboxypeptidases (MCP) of the M32 family of peptidases have been identified in a number of prokaryotic organisms but they are absent from eukaryotic genomes with the remarkable exception of those of trypanosomatids. The genome of Trypanosoma brucei, the causative agent of Sleeping Sickness, encodes one such MCP which displays 72% identity to the characterized TcMCP-1 from Trypanosoma cruzi. As its orthologue, TcMCP-1, Trypanosoma brucei MCP is a cytosolic enzyme expressed in both major stages of the parasite. Purified recombinant TbMCP-1 exhibits a significant hydrolytic activity against the carboxypeptidase B substrate FA (furylacryloil)-Ala-Lys at pH 7.0-7.8 resembling the T. cruzi enzyme. Several divalent cations had little effect on TbMCP-1 activity but increasing amounts of Co 2+ inhibited the enzyme. Despite having similar tertiary structure, both protozoan MCPs display different substrate specificity with respect to P1 position. Thus, TcMCP-1 enzyme cleaved Abz-FVK-(Dnp)-OH substrate (where Abz: o-aminobenzoic acid and Dnp: 2,4-dinitrophenyl) whereas TbMCP-1 had no activity on this substrate. Comparative homology models and sequence alignments using TcMCP-1 as a template led us to map several residues that could explain this difference. To verify this hypothesis, site-directed mutagenesis was undertaken replacing the TbMCP-1 residues by those present in TcMCP-1. We found that the substitution A414 M led TbMCP-1 to gain activity on Abz-FVK-(Dnp)-OH, thus showing that this residue is involved in specificity determination, probably being part of the S1 sub-site. Moreover, the activity of both protozoan MCPs was explored on two vasoactive compounds such as bradykinin and angiotensin I resulting in two different hydrolysis patterns. © 2012 Elsevier B.V. All rights reserved.

Contribution of macroporosity to water flux of a soil under different tillage systems; Contribuição da macroporosidade para o fluxo total de água em um solo sob diferentes sistemas de preparo Soracco, Carlos Germán; Lozano, Luis Alberto; Balbuena, Roberto Hernan; Ressia, Juan Manuel; Filgueira, Roberto Raul In view of the importance of the macroporosity for the water transport properties of soils, its quantitative assessment is a challenging task. Measurements of hydraulic conductivity (K) at different soil water tensions and the quantification of water-conducting macropores (..M)of a soil under different tillage systems could help understand the effects on the soil porous system and related hydraulic properties. The purpose of this study was to assess the effects of Conventional Tillage (CT), Chisel Plow (CP) and No Tillage (NT) on ..M and on K; and to quantify the contribution of macroporosity to total water flux in a loam soil. A Tension disc infiltrometer was used at two soil water pressure heads (-5 cm, and 0) to infer ..Mand K, during fallow. Macroporosity was determined based on the flow contribution between 0 and -5 cm water potentials (K0,K5, respectively), according to the Hagen- Poiseuille equation. The K0 values were statistically higher for CT than for NT and CP. The K5 values did not differ statistically among treatments. The mean K values varied between 0.20 and 3.70 cm/h. For CT, ..M was significantly greater than for CP and NT, following the same trend as K0. No differences in ..M were detected between CP and NT. With CT, the formation of water-conducting macropores with persistence until post-harvest was possible, while under CP preparation, the waterconducting macropores were not persistent. These results support the idea that tillage affects the soil water movement mainly by the resulting water-conducting macropores. Future studies on tillage effects on water movement should focus on macroporosity.; A importância da macroporosidade para o transporte de água no solo faz a sua avaliação de forma quantitativa uma tarefa desafiadora. Os valores da condutividade hidráulica (K) do solo em diferentes potenciais de retenção de água no solo e a quantificação de macroporos condutores de água (θM) em diferentes sistemas de preparo do solo proporcionarão melhor compreensão dos efeitos no arranjo de poros e nas propriedades físico-hídricas do solo. Dessa forma, o objetivo deste estudo foi avaliar os efeitos de um preparo convencional do solo com arado de aivecas (CT), com subsolador (CP) e utilizando um sistema com plantio direto (NT) sobre os atributos θM e K, bem como quantificar a contribuição da macroporosidade para o fluxo total de água em um solo franco. Um infiltrômetro de tensão no solo foi utilizado para emitir duas pressões ascendentes de água (-5 cm e 0 cm) para inferir θM e K, durante o pousio. A macroporosidade foi determinada com base na contribuição do fluxo entre os potenciais de água de 0 e -5 cm (K0 e K5, respectivamente), de acordo com a equação de Hagen-Poiseuille. Os valores da K0 obtidos foram estatisticamente superiores no preparo CT, quando comparados aos valores do NT e do CP. Os valores da K5 não diferiram estatisticamente entre os tipos de preparo. Os valores médios da K variaram entre 0,20 e 3,70 cm/h. A quantificação de macroporos condutores de água (θM) foi significativamente superior para o preparo CT em relação aos preparos CP e NT, seguindo a mesma tendência da K0. Não foram detectadas diferenças significativas dos valores de θM entre os preparos CP e NT. Utilizando o preparo CT, foi possível a formação de macroporos condutores de água com persistência até a pós-colheita; já no preparo CP, os macroporos condutores de água não foram persistentes. Os resultados apresentados sustentam a hipótese de que o sistema de preparo do solo escolhido altera o movimento da água no solo, principalmente, devido à formação de macroporos condutores de água. Estudos futuros sobre o efeito do sistema de preparo relacionado ao movimento da água no solo devem-se concentrar nas condições de formação da macroporosidade do solo.

Inactivation of tyrosinase photoinduced by pterin Dantola, Maria Laura; Gojanovich, Aldana Daniela; Thomas, Andrés Héctor Tyrosinase catalyzes in mammals the first and rate-limiting step in the biosynthesis of the melanin, the main pigment of the skin. Pterins, heterocyclic compounds able to photoinduce oxidation of DNA and its components, accumulate in the skin of patients suffering from vitiligo, a chronic depigmentation disorder in which the protection against UV radiation fails due to the lack of melanin. Aqueous solutions of tyrosinase were exposed to UV-A irradiation (350. nm) in the presence of pterin, the parent compound of oxidized pterins, under different experimental conditions. The enzyme activity in the irradiated solutions was determined by spectrophotometry and HPLC. In this work, we present data that demonstrate unequivocally that the enzyme is photoinactivated by pterin. The mechanism of the photosensitized process involves an electron transfer from tyrosinase to the triplet excited state of pterin, formed after UV-A excitation of pterin. The biological implications of the results are discussed.

Multi-century tree-ring based reconstruction of the Neuquén River streamflow, northern Patagonia, Argentina Mundo, Ignacio Alberto; Masiokas, Mariano Hugo; Villalba, Ricardo; Morales, Mariano Santos; Neukom, R.; Le Quesne, C.; Urrutia, R. B.; Lara, A. In most cases, gauged river flow records in southern South America extend for only a few decades, hampering the detection of long-term, decadal to centennial-scale cycles and trends. Long streamflow series can be reconstructed from tree-ring records, offering the opportunity of extending the limited hydrological instrumental data to several centuries. In northern Patagonia, Argentina, the Neuquén River has great importance for local and national socio-economic activities such as hydroelectric power generation, agriculture and tourism. In this study, new and updated tree-ring chronologies from Araucaria araucana and Austrocedrus chilensis are used to reconstruct the October-June mean streamflow for the Neuquén River and place the period of gauged flows (1903-2009), in a long-term, multi-century context. The reconstruction covers the period 1346-2000 AD and was developed from a network of 43 tree-ring chronologies, grouped in composite series, using a nested principal component regression approach. Analyses of the frequency, intensity, and duration of droughts and pluvial events indicate that the 20th century contains some of the driest and wettest annual to decadal-scale events in the last 654 yr, but longer and more severe events were recorded in previous centuries. Blackman-Tukey and singular spectral analyses identified quasiperiodic oscillations from 3.5 to 17.5 yr. A dominant 6.8-yr cycle explains ca. 23.6% of the total variance in the Neuquén River streamflow reconstruction. Correlation analyses showed that discharges of the Neuquén River are related to variations in the Southern Annular Mode (SAM), a measure of air mass exchanges between middle and high latitudes in the Southern Hemisphere. This association is consistent with previous studies that indicate a strong correlation between rainfall in northern Patagonia and SAM variations.

Implementation and evaluation of protocols translating: Methods for IPv4 to IPv6 transition Perez Monte, Cristian Federico; Robles, Maria Ines; Mercado, Gustavo Ariel; Taffernaberry, Juan Carlos; Orbiscay, Marcela Alejandra; Tobar, Mario Sebastián; Moralejo, Raúl; Pérez, Santiago Today millions of computers are interconnected using the Internet Protocol version 4 (IPv4) and can not switch to the new version, IPv6, simultaneously. For this reason the IETF has defined a number of mechanisms for transitioning to the new protocol in a progressively and controlled manner. On the other hand, Internet Service Providers (ISP) will not have new IPv4 global addresses to offer in the near future due to the fact that these addresses will be exhausted [1]. A very interesting alternative for ISPs is to use IPv6 global addresses and, by some transitional method, access the current IPv4 backbone. This study aims to compare two methods of transparent access to the IPv4 Internet backbone, from networks that are "IPv6 only". To make the comparison, a software was developed, implementing an Application Layer Gateway (ALG), and Ecdysis was used to implement NAT64. Both trials used a network IPv6 Test Bed. This paper details the design principles and fundamental aspects of the ALG implementation, as well as the implementation of NAT64. Finally, we present the tests performed and conclusions drawn on the test platform.

L'anthropologie théologique de Gaudium et spes Segovia, Juan Fernando Du concile Vatican II à aujourd’hui, la constitution Gaudium et spes1 a représenté la pierre angulaire de la doctrine sociale et politique de l’Eglise. Selon les termes de Jean-Paul II, elle est « la Magna Carta de la dignité humaine »2. Depuis 1965, « Gaudium et spes trace le visage d’une Église “intimement solidaire du genre humain et de son histoire”, qui chemine avec toute l’humanité et qui est sujette, avec le monde, au même sort terrestre, tout en étant “le ferment et, pour ainsi dire, l’âme de la société humaine appelée à être renouvelée dans le Christ et transformée en famille de Dieu” »3 . Quant à la clé de compréhension de Gaudium et spes, c’est la personne : « Tout [y] est considéré à partir de la personne et en direction de la personne, “seule créature sur terre que Dieu a voulue pour elle-même”. La société, ses structures et son développement doivent être +nalisés à “l’essor de la personne”. Pour la première fois, le Magistère de l’Église, à son plus haut niveau, s’exprime de manière aussi large sur les di0érents aspects temporels de la vie chrétienne : “On doit reconnaître que l’attention apportée par la Constitution aux changements sociaux, psychologiques, politiques, économiques, moraux et religieux a stimulé toujours plus […] la préoccupation pastorale de l’Église pour les problèmes des hommes et le dialogue avec le monde”

Caracterización altitudinal, uso y conservación de las Yungas subtropicales de Argentina; Altitudinal characterization, use and conservation of subtropical Yungas of Argentina Malizia, Lucio Ricardo; Pacheco, S.; Blundo, Cecilia Mabel; Brown, Alejandro Diego Las Yungas subtropicales se extienden por el noroeste de Argentina y sur de Bolivia, ocupando aproximadamente 56 000 km2. Se caracterizan por su amplia distribución altitudinal (400-2300 msnm), donde el recambio de especies de árboles determina la ocurrencia de tres pisos altitudinales (selva pedemontana, selva montana y bosque montano) con cambios consistentes en la fenología foliar y los síndromes de dispersión de las especies arbóreas. Dominan las especies caducifolias en los extremos del gradiente, y las especies semicaducifolias y siempreverdes en las elevaciones intermedias. Por su parte, las especies dispersadas por el viento o la gravedad caracterizan la parte baja del gradiente, mientras que las dispersadas por animales caracterizan los pisos superiores de vegetación. Los cambios físicos y biológicos en el gradiente altitudinal condicionan los usos y las estrategias de conservación de las Yungas subtropicales. La desforestación alcanzaba 18% de la superficie original de este ambiente en Argentina en la década de los 70 y 31% en el año 2010, principalmente (>90%) en las zonas bajas y planas. Las Yungas de Argentina presentan protección formal estatal (nacional, provincial y municipal) en 22% de su extensión actual, sin considerar las categorías internacionales, que pueden ser instrumentos valiosos, si se logra una implementación efectiva de los criterios de uso sustentable de los recursos naturales. Adicionalmente, los planes de ordenamiento territorial en marcha vinculados a compensaciones económicas podrían jugar un papel importante en el marco de estrategias regionales de uso y conservación.; Subtropical Yungas are distributed in northwestern Argentina and southern Bolivia over approximately 56000 km2. This vegetation type expands across a large altitudinal gradient (400-2300 m asl), where tree species turnover promotes the occurrence of three altitudinal belts (pre-montane forest, lower montane forest and upper montane forest), with associated changes in leaf phenology and dispersal syndromes. Deciduous tree species are dominant at the extremes of the gradient, and semi-deciduous and evergreen species are dominant at mid elevations. Alternatively, wind- and gravity-dispersed tree species characterize the lower part of the gradient, while animal-dispersed trees characterize the upper part of the gradient. Physical and biological changes along the altitudinal gradient determine uses and conservation strategies. Deforestation of subtropical Yungas reached 18% of the original distribution in Argentina during the 1970’s, and raised up to 31% by 2010, mainly (>90%) over low and flat areas. To date, 22% of the current distribution of Argentinean Yungas is formally protected (at national, provincial and municipal levels), not including international categories that may prove useful if sustainable-use criteria are successfully implemented. Additionally, land-use plans articulated with economic compensations might play a key role for planning regional use and conservation of subtropical Yungas.

Anisotropy and relaxation processes of uniaxially oriented CoFe2O4 nanoparticles dispersed in PDMS Antonel, Paula Soledad; Negri, Ricardo Martin; Leyva de Guglielmino, Ana Gabriela; Jorge, Guillermo Antonio When a uniaxial magnetic field is applied to a non-magnetic dispersive medium filled with magnetic nanoparticles, they auto-assemble into thin needles parallel to the field direction, due to the strong dipolar interaction among them. We have prepared in this way magnetically oriented nanocomposites of nanometer-size CoFe 2O 4 particles in a polydimethylsiloxane polymer matrix, with 10% w/w of magnetic particles. We present the characteristic magnetic relaxation curves measured after the application of a magnetic field forming an angle α with respect to the needle direction. We show that the magnetic viscosity (calculated from the logarithmic relaxation curves) as a function of α presents a minimum at α=0, indicating slower relaxation processes associated with this configuration of fields. The results seems to point out that the local magnetic anisotropy of the nanoparticles is oriented along the needles, resulting in the macroscopic magnetic anisotropy observed in our measurements.

Guiding authors to reliably use taxonomic names Bortolus, Alejandro It is widely known that every scientific work must be verifiable and repeatable by following the details included in the Materials and Methods section. Yet despite this, a high proportion of papers dealing with species in ecology and evolution omit the taxonomic materials and methods used to validate the names of the taxa mentioned, which is likely to have negative impacts on scientific ideas, global biodiversity, and human welfare.

Retroceso de la línea de costa en las Grütas, provincia de Río Negro; Retreat of the line of coast in Las Grutas, Río Negro province Kokot, Roberto Roque; Chomnalez, Florencia La localidad de Las Grutas, ubicada en la provincia de Río Negro, presenta una costa acantilada con una extensa plataforma litoral. Estas geoformas están constituidas por sedimentitas paleógenas correspondientes a la Formación Gran Bajo del Gualicho. Sobre las mismas se apoyan en discordancia erosiva depósitos de cordones litorales pleistocenos y la secuencia culmina con depósitos de dunas holocenos. Mediante la comparación de fotografías aéreas e imágenes satelitales, se determinó el grado de erosión entre los años 1969 y 2008. El retroceso fue estudiado a través de la comparación de fotografías aéreas e imágenes satelitales georreferenciadas. Los resultados muestran una tendencia a la reducción de los campos de dunas, al retroceso de las plataformas litorales y de la línea de costa. Esta última presenta una tasa de erosión media de 1,50 m en el lapso de 39 años. Sin embargo, los sectores céntricos y septentrionales fueron más afectados alcanzando hasta 3 m de retroceso en ese período. La erosión y los consecuentes procesos de remoción en masa responden principalmente a la intensa acción del oleaje sobre los afloramientos costeros, especialmente en los sectores de costa más expuestos a las rompientes, así como a los condicionantes geológico/estructurales de los afloramientos expuestos. El escenario de peligrosidad es acentuado por la acción antrópica que contribuye con la aceleración de los procesos naturales.; The town of Las Grutas, province of Río Negro, has a cliffed coastline with an extensive coastal platform. Mentioned land-forms are formed above Paleogene sedimentary rocks for the Gran Bajo del Gualicho Formation. Rely on them in erosive unconformity Pleistocene beach ridges deposits and the sequence ends with Holocene dune deposits. By comparing aerial photographs and satellite images, it was determined that the coast was eroded from 1969 to nowadays. The retreat was studied by comparing aerial photographs and georeferenced satellite imagery. The results show a downward trend of the dunes, the retreat of shore platforms and coastal shoreline. The latter has an average erosion rate of 1.50 m in 39 years. However, the central and northern sectors are most affected reaching up to 3 m setback in the same period. These erosion and resulting mass movement processes respond mainly to intense wave action on coastal outcrops, especially in coastal areas most exposed to the breakers, as well as the determining geological/structural outcrops exposed. The dangerous scenario is exacerbated by human action that contributes to the acceleration of the natural processes.

Fructose rich diet-induced high plasminogen activator inhibitor-1 (PAI-1) production in the adult female rat: Protective effect of progesterone Castrogiovanni, Daniel Cayetano; Alzamendi, Ana; Ongaro Gambino, Luisina; Giovambattista, Andres; Gaillard, Rolf C.; Spinedi, Eduardo Julio The effect of progesterone (P4) on fructose rich diet (FRD) intake-induced metabolic, endocrine and parametrial adipose tissue (PMAT) dysfunctions was studied in the adult female rat. Sixty day-old rats were i.m. treated with oil alone (control, CT) or containing P4 (12 mg/kg). Rats ate Purina chow-diet ad libitum throughout the entire experiment and, between 100 and 120 days of age drank ad libitum tap water alone (normal diet; CT-ND and P4-ND) or containing fructose (10% w/v; CT-FRD and P4-FRD). At age 120 days, animals were subjected to a glucose tolerance test or decapitated. Plasma concentrations of various biomarkers and PMAT gene abundance were monitored. P4-ND (vs. CT-ND) rats showed elevated circulating levels of lipids. CT-FRD rats displayed high (vs. CT-ND) plasma concentrations of lipids, leptin, adiponectin and plasminogen activator inhibitor-1 (PAI-1). Lipidemia and adiponectinemia were high (vs. P4-ND) in P4-FRD rats. Although P4 failed to prevent FRD-induced hyperleptinemia, it was fully protective on FRD-enhanced plasma PAI-1 levels. PMAT leptin and adiponectin mRNAs were high in CT-FRD and P4-FRD rats. While FRD enhanced PMAT PAI-1 mRNA abundance in CT rats, this effect was absent in P4 rats. Our study supports that a preceding P4-enriched milieu prevented the enhanced prothrombotic risk induced by FRD-elicited high PAI-1 production.

Los riesgos y las venturas del poeta contemporáneo: Dilemas en torno a la figura del escritor en la revista Poesía Buenos Aires (1950-1960) Bonano, Mariana El ideario vanguardista del grupo de escritores constituido en torno a la revista argentina Poesía Buenos Aires (1950-1960) puede ser delimitado a partir de las figuraciones acerca del poeta y de la labor creadora, presentes en los textos programáticos y de carácter ensayístico que la publicación recoge a lo largo de sus treinta números. Teniendo en cuenta aspectos de la doctrina susceptibles de ser vinculados con aquellos que las vanguardias históricas reivindican (compromiso vital, inconformismo, rechazo de todo tipo de convencionalismos), el presente trabajo examina la construcción en las páginas de la revista de un modelo de escritor próximo al arquetipo del "poeta maldito" conformado en la Modernidad y cultivado por las figuras más relevantes del simbolismo francés. En esta dirección, indaga en los retratos de poetas y propone que dichas figuraciones, en parte destinadas a fundamentar el valor de la empresa impulsada por los realizadores, dan cuenta al mismo tiempo del desgarramiento de los productores culturales quienes, situados frente la cultura de masas propiciada por el peronismo de la década de 1950, reivindican la "actitud ética" del escritor que hace de su creación un modo de vida y atribuyen a su práctica simbólica una misión redentora y liberadora. El artículo muestra que tal posicionamiento, pasible de ser identificado con el que asumen los miembros del grupo editor, no llega a resolver una de las problemáticas caras a la publicación: la de la constitución de una "poesía nueva" capaz de integrar la experiencia caótica del mundo contemporáneo y de restituir a la vez la comunicación esencial entre los hombres.

Estudio comparativo sobre los estilos de aprendizaje de estudiantes universitarios argentinos de diferentes disciplinas; Comparative study on the learning styles of argentine university students from different disciplines Ventura, Ana Clara; Moscoloni, Nora Ana Maria; Gagliardi, Raul Pedro La alfabetización académica exige el dominio progresivo de las formas textuales y discursivas propias de cada disciplina. El objetivo de este estudio es indagar los estilos de aprendizaje de estudiantes universitarios, estableciendo comparaciones según el tipo de episteme (Ciencias Humanas-Ciencias Exactas). Se realizó un estudio descriptivo-correlacional de corte transversal. Se aplicó el Inventario de Estilos de Aprendizaje de Felder y Soloman (1998) a 62 estudiantes de Ingeniería y 71 de Psicología de primer año de una universidad pública argentina. Los estudiantes inician su formación académica con distintos estilos de aprendizaje. Las discrepancias encontradas se acentuaron según el tipo de disciplina, y se obtuvieron diferencias estadísticamente significativas en los estilos de percepción (sensorial-intuitivo), representación (visual-verbal)y comprensión (secuencial-global). Los estudiantes de Ingeniería se definieron como sensoriales y visuales; en cambio, las orientaciones en Psicología son intuitivas, verbales y secuenciales. Implicancias educativas son discutidas.; Academic literacy requires the progressive mastery of textual and discursive forms of each discipline. The aim of this study is to analyze the learning styles of college students, comparing them by type of episteme (Human Sciences- Sciences). The research was a descriptive-correlational study with a transversal design. We applied the Index of Learning Styles of Felder & Silverman (1998) to 62 engineering students and 71 psychology students of first-year of a public university in Argentina. The main results show that students begin higher education with different learning styles. The discrepancies found were accentuated by the type of discipline; obtaining statistically significant differences in the styles of perception (sensory-intuitive), representation (visual-verbal) and comprehension (sequential-global).The engineering students were defined as sensory and visual. Instead, the guidelines in Psychology are intuitive, verbal, and sequential. Educational implications are discussed.