Rheological behaviorandbondingperformanceofanalkalinesoy proteinsuspension Bacigalupe, Alejandro; Poliszuk, Andrea K.; Eisenberg, Patricia; Escobar, Mariano Martin The goal of this work is to study the rheological properties of based-modified soy protein concentrate (SPC) adhesives and the relationship between viscoelastic properties and bonding performance. Chemical modification of SPC with sodium hydroxide was made to evaluate the effect of alkali on the viscoelastic properties. Viscosity and solubility depends directly of the 3D structure and the isoelectric point (pI) of the protein. Results show that viscosity is strongly pH dependant due to the protein unfolding. Solubility profiles exhibit the typical U-shaped curve, being higher on either side of isoelectric point. Fourier transformed infrared analysis was used to analyze Amide I (1720-1600 cm-1) and Amide III (1400-1200cm-1) band patterns which reflect the different secondary structures in proteins. The intensity of the band at 1250 cm-1 increases with respect to that at 1235 cm-1 for higher pH values. This could be associated with the destruction, at least partially, of the β-sheet structure. Bonding performance was measured in dry conditions and the wetting properties were analyzed by scanning electron microscopy. The bonding performance improves when the SPC is stabilized at pH 12 due to the protein unfolding, revealing a strong interaction between the secondary structure and the wood surface. As part of an ongoing project it was concluded that alkali modification is a suitable procedure to modify a protein suspension, improving application conditions and mechanical properties of bioadhesives of a semistructural type.

Circuitos de consagración académica: las revistas en ciencias sociales y humanas de Argentina; Segmented circuits of academic recognition: the journals of social sciences and humanities in Argentina Beigel, Maria Fernanda; Salatino, Javier Maximiliano En otros estudios, hemos analizado cómo la "periferialidad" científica ha devenido en un fenómeno cada vez complejo, que no se restringe a una dinámica espacial-nacional y mal puede explicarse con el concepto de "imperialismo académico". El Sistema Académico Mundial se fue estructurando en circuitos, a través de un triple principio de jerarquización, construido históricamente en la intersección de la institución de origen, la lengua y la disciplina. Así, se fue jerarquizando el circuito autodenominado "mainstream", sobre la base de la diferenciación entre científicos internacionalizados e investigadores restringidos a circuitos nacionales o "marginales". En este trabajo, nos enfocamos en el universo de revistas de ciencias sociales y humanas en la Argentina con el fin de profundizar el estudio de la dinámica disciplinar de ese principio de jerarquización. En la primera parte, proponemos una clasificación de circuitos de circulación de acuerdo con su poder de consagración académica, para ir más allá de una mera medición de "visibilidad". Luego, desarrollamos un análisis de la base de datos que hemos construido con todas las revistas argentinas para determinar en qué circuitos circula ese conocimiento. Observamos, en particular, un circuito local muy fuerte, con poca o nula repercusión internacional, constituido por revistas editadas en papel, sin indexación y con una distribución restringida.; In other studies we have analysed to which extent scientific “peripherality” has become an increasingly complex phenomenon that is not restricted to national dynamics and cannot be explained with the concept of “academic imperialism”. The World Academic System was structured in the last four decades through a triple principle of hierarchy that created segmented circuits, historically constructed at the intersection of the institution of origin, language and discipline. The so-called “mainstream” circuit was based on the distinction between internationalized scientists and researchers restricted to domestic or “marginal” circuits. In this paper, we focus on the world of social science journals in Argentina in order to deepen our insight on the disciplinar specificity of that principle of hierarchy. In the first part, we describe the circuits according with their power of “international” recognition, in order to go beyond a mere measurement of “visibility”. Then, we develop an analysis of the database that we have built with the universe of Argentine journals to determine how this knowledge circulates. We observe, particularly, a strong domestic circuit, with little or none international impact, consisting of non- indexed journals published only in paper, resulting in a very restricted distribution.

Contexto productivo argentino: El caso de los sistemas de iluminación natural Ferron, Leandro Martin El presente trabajo expone la problemática de la fabricación de Sistemas para el aprovechamiento de la Iluminación Natural en el entorno la producción industrial a nivel regional en la República Argentina. Se presenta una síntesis de las políticas implementadas sobre el sector productivo y su relación con el ámbito de investigación estatal. Se elabora una clasificación de los mencionados sistemas y analizan los resultados de entrevistas a los responsables de producción de talleres regionales. El aporte más relevante es el de verificar la factibilidad de producción regional de sistemas de iluminación natural basada en las capacidades tecnológicas de la industria, tendientes al ahorro energético destinado a iluminación en edificios comerciales y residenciales.; Automatic pitch recognition provides mechanisms for recognizing notes played by musical instruments. This paper explains how to embedd a pitch recognition algorithm in a project using the C implementation of SWIPEP. The chosen project is a memory game in which user has to listen to a sequence of notes and play them back to the computer using a soprano recorder flute. Additionally we explain the basic concepts for understanding the acoustic phenomena involved. This paper was written for all students with basic programming knowledge who want to incorporate sound processing to their projects.

Resistance of functional Lactobacillus plantarum strains against food stress conditions Ferrando, Verónica Andrea; Quiberoni, Andrea del Lujan; Reinheimer, Jorge Alberto; Suárez, Viviana Beatriz The survival of three Lactobacillus plantarum strains (Lp 790, Lp 813 and Lp 998) with functional properties was studied taking into account their resistance to thermal, osmotic and oxidative stress factors. Stress treatments applied were: 52°C-15min (Phosphate Buffer pH 7, thermal shock), H2O2 0.1% (p/v) - 30min (oxidative shock) and NaCl aqueous solution at 17, 25 and 30% (p/v) (room temperature - 1h, osmotic shock). The osmotic stress was also evaluated on cell growth in MRS broth added of 2, 4, 6, 8 and 10% (p/v) of NaCl, during 20h at 30°C. The cell thermal adaptation was performed in MRS broth, selecting 45°C for 30min as final conditions for all strains. Two strains (Lp 813 and Lp 998) showed, in general, similar behaviour against the three stress factors, being clearly more resistant than Lp 790. An evident difference in growth kinetics in presence of NaCl was observed between Lp 998 and Lp 813, Lp998 showing a higher optical density (OD570nm) than Lp 813 at the end of the assay. Selected thermal adaptation improved by 2 log orders the thermal resistance of both strains, but cell growth in presence of NaCl was enhanced only in Lp 813. Oxidative resistance was not affected with this thermal pre-treatment. These results demonstrate the relevance of cell technological resistance when selecting presumptive "probiotic" cultures, since different stress factors might considerably affect viability or/and performance of the strains. The incidence of stress conditions on functional properties of the strains used in this work are currently under research in our group.

The peril of PCR inhibitors in environmental samples: the case of Didymosphenia geminata Jones, Leandro Roberto; Uyua, Noelia Mariel; Manrique, Julieta Marina Since the introduction of polymerase chain reaction (PCR) biodiversity study has been significantly influenced by the chance of generating unprecedented amounts of molecular data. Although it is a robust technique, those applications requiring high sensitivity and reproducibility, that is PCR detection and quantitative PCR, can be negatively affected by PCR inhibition. This is particularly challenging for diverse kinds of samples included the environmental ones, which usually contain complex mixtures of a variety of inhibitory substances. The problem of PCR inhibition can be overcome, or ameliorated, by implementing adequate protocols of nucleic acids purification, internal controls and modern analytical approaches focused on PCR kinetics. Herein, we remark these procedures and describe the general techniques that can be used to optimize DNA extraction protocols for PCR applications. In addition, we show that PCR inhibition might have negative consequences in molecular studies of Didymosphenia geminata, an invasive microalga that have recently developed massive blooms in temperate regions worldwide, and provide general guidelines for dealing with this problem.

Pressurized hot water extraction of anthraquinones from Heterophyllaea pustulata Hook f. (Rubiaceae) Barrera Vazquez, Maria Fernanda; Comini, Laura Raquel; Milanesio, Juan Manuel; Núñez Montoya, Susana Carolina; Cabrera, Jose Luis; Bottini, Susana Beatriz; Martini, Raquel Evangelina Heterophyllaea Pustulata Hook. f. (Rubiaceae), commonly known as "cegadera", is a phototoxic native plant from South America, containing anthraquinones with important antibacterial, antiviral and anticancer activity. In this work, pressurized hot water extraction (PHWE) was applied to extract anthraquinones from the stems of the plant. The effect of temperature, pressure and water flow rate on the extraction yield of four anthraquinones (soranjidiol, rubiadin, rubiadin 1-methyl ether and 2-hydroxy-3-methyl anthraquinone) was studied. Within the experimental range explored, the optimum extraction temperature was 170 ºC. Lower yields were obtained at higher temperatures, apparently due to the thermal decomposition of these anthraquinones. The experimental extraction curves were fitted with three models: the thermodynamic partitioning and the one-site and two-site kinetic models.

The social value of biodiversity and ecosystem services from the perspectives of different social actors Caceres, Daniel Mario; Tapella, Esteban; Quétier, Fabien; Díaz, Sandra Myrna A vast literature is now available on ecosystem services (ES), their potential as a tool for analyzing intertwined processes of ecological and social change, and their monetary valuation. Much less is known about the social value of different ES for different social actors (SA), and their links with specific components of biodiversity. We unpack the social aspects of an interdisciplinary and multi-SA methodology that allows us to assess how different SA perceive and value different ES, and how they associate them with different components of biodiversity, ecological attributes, and ecosystem types. We apply the methodology to a study area in the Gran Chaco region of South America, presenting original social-ecological information from the field. Being affected by the rapid and widespread expansion of agribusiness over the woody ecosystems of southern South America, this location provides a policy-relevant context in which to test our approach. We identified six major ecosystem types and five relevant SA. We carried out 163 individual in-depth interviews and ran seven single-actor focus groups. We identified 116 ES, which were then aggregated into 22 more general categories. Although all SA perceived all ecosystem types as multifunctional, they showed markedly different perceptions of and interests in the ES provided by them. Subsistence farmers and extension officers valued a large number of ES primarily provided by the most pristine ecosystems. Members of conservation agencies and policymakers also identified a wide range of ES, spanning all ecosystem types. However, large farmers and cattle ranchers recognized a dependency on only a small number of ES. Therefore, the rapid expansion of agribusiness occurring in this region is a threat to a large number of ES considered valuable by a wide range of SA. Without necessarily having to resort to monetary valuation, our methodology provides a rigorous quantitative-qualitative way to compare the perspective of different SA, including scientists, and is thus useful for social-ecological assessment and action.

Análisis morfológico del complejo volcánico La Hoyada puna austral mediante la aplicación de modelos de elevación digital; Using digital elevation models for morphological analysis of La Hoyada Volcanic Complex Bustos, Emilce; Arnosio, José Marcelo; Norini, Gianluca Las formas volcánicas resultan del balance de procesos constructivos y destructivos que afectan a los edificios volcánicos, por lo tanto el estudio de los rasgos volcánicos contribuye al entendimiento de la evolución del volcanismo de una zona. El Complejo Volcánico La Hoyada (Mioceno superior-Plioceno) se encuentra en el flanco oriental de la cordillera de San Buenaventura, en la provincia de Catamarca, Argentina. Esta contribución presenta una aplicación de modelos de elevación digital para el análisis morfológico del Complejo Volcánico La Hoyada, con el objetivo de identificar y evaluar las formas volcánicas de la región, para entender la evolución de este complejo volcánico antiguo con respecto a las manifestaciones volcánicas de la zona. El análisis morfológico se realizó usando los modelos de elevación digital ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) y SRTM (Shuttle Radar Topographic Mission), además de la evaluación de imágenes SPOT. Se realizaron distintos productos derivados de los modelos de elevación digital para llevar a cabo la identificación de morfologías areales. A través del análisis de los datos se identificaron 6 dominios morfológicos, cada uno representa un volcán individual de este Complejo. La actividad tectónica de la Puna Austral y el volcanismo moderno de la zona son los factores responsables de la destrucción de estos edificios volcánicos. Los rasgos volcánicos están mejor preservados hacia el norte del complejo, por lo tanto el grado de conservación podría indicar una migración de la evolución del volcanismo de sur a norte. Esta metodología constituye una herramienta fundamental para comprender la evolución volcánica de complejos volcánicos erodados de larga duración.; Volcanoes´ shapes result from constructional and destructional events; consequently, the study of volcanic features gives insight into the volcanic evolution. La Hoyada Volcanic Complex (Upper Miocene- Pliocene) is located in the eastern flank of San Buenaventura ridge, in Catamarca, Argentina. This study shows an application of digital elevation models for the volcanic area La Hoyada. The aim of this study is to examine the volcanic landforms because volcanic feature understanding of La Hoyada Volcanic Complex is an important tool for unravelling the evolution of this ancient and eroded volcanic complex. Morphological analysis of La Hoyada was performed using ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) and SRTM (Shuttle Radar Topographic Mission) Digital Elevation Models. The morphological evaluation was complemented by using high resolution images SPOT. Several products were derived from both Digital Elevation Models to identify areal morphologies. Through the evaluation of Digital Elevation Models derived data, as much as 6 morphological domains can be recognized each one representing a single volcano.Tectonic activity and modern volcanism in this area are responsible for the destruction of the volcanic edifices of La Hoyada. The partially conserved volcanic features are more distinguishable towards the north; hence, the grade of preservation could indicate that the evolution of this volcanic center was from south to north. This methodology provides a powerful tool for understanding the volcanic evolution of eroded long-lived volcanic complexes.

Plant identification based on leaf midrib cross-section images using fractal descriptors Silva, Núbia Rosa Da; Florindo, João Batista; Gómez, María Cecilia; Rossatto, Davi Rodrigo; Kolb, Rosana Marta; Bruno, Odemir Martinez The correct identification of plants is a common necessity not only to researchers but also to the lay public. Recently, computational methods have been employed to facilitate this task, however, there are few studies front of the wide diversity of plants occurring in the world. This study proposes to analyse images obtained from cross-sections of leaf midrib using fractal descriptors. These descriptors are obtained from the fractal dimension of the object computed at a range of scales. In this way, they provide rich information regarding the spatial distribution of the analysed structure and, as a consequence, they measure the multiscale morphology of the object of interest. In Biology, such morphology is of great importance because it is related to evolutionary aspects and is successfully employed to characterize and discriminate among different biological structures. Here, the fractal descriptors are used to identify the species of plants based on the image of their leaves. A large number of samples are examined, being 606 leaf samples of 50 species from Brazilian flora. The results are compared to other imaging methods in the literature and demonstrate that fractal descriptors are precise and reliable in the taxonomic process of plant species identification.

Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary Amarilla, Leonardo; Anton, Ana Maria Ramona; Chiapella, Jorge Oscar; Manifesto, María; Angulo, Diego F.; Sosa, Victoria The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species? range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2?1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity.

Draft genome sequence of Inquilinus limosus strain MP06, a multidrug-resistant clinical isolate Pino, Marylú; Di Conza, José Alejandro; Gutkind, Gabriel Osvaldo The bacterium, Inquilinus limosus, with its remarkable antimicrobial multiresistant profile, has increasingly been isolated in cystic fibrosis patients. We report draft genome sequence of a strain MP06, which is of considerable interest in elucidating the associated mechanisms of antibiotic resistance in this bacterium and for an insight about its persistence in airways of these patients.

Sex-specific recombination maps for individual macrochromosomes in the Japanese quail (Coturnix japonica) del Priore, Lucía; Pigozzi, Maria Ines Meiotic recombination in the Japanese quail was directly studied by immunolocalization of mutL homolog 1 (MLH1), a mismatch repair protein of mature recombination nodules. In total, 15,862 crossovers were scored along the autosomal synaptonemal complexes in 308 meiotic nuclei from males and females. Crossover frequencies calculated from MLH1 foci show wide similitude between males and females with slightly higher number of foci in females. From this analysis, we predict that the sex-averaged map length of the Japanese quail is 2580 cM, with a genome-wide recombination rate of 1.9 cM/Mb. MLH1 focus mapping along the six largest bivalents showed few intersex differences in the distribution of crossovers along with variant patterns in metacentric and acrocentric macrobivalents. These results provide valuable information to complement linkage map analysis in the species while providing insight into our understanding of the mechanisms of crossover distribution along chromosome arms.

The rise and fall of arbuscular mycorrhizal fungal diversity during ecosystem retrogression Kruger, Manuela; Teste, Francois; Laliberté, Etienne; Lambers, Hans; Coghlan, Megan; Zemunik, Graham; Bunce, Michael (P) limitation of primary productivity. Arbuscular mycorrhizal fungi (AMF) enhance P acquisition for most terrestrial plants, but it has been suggested that this strategy becomes less effective in strongly weathered soils with extremely low P availability. Using next generation sequencing of the large subunit ribosomal RNA gene in roots and soil, we compared the composition and diversity of AMF communities in three contrasting stages of a retrogressive >2-million-year dune chronosequence in a global biodiversity hotspot. This chronosequence shows a ~60-fold decline in total soil P concentration,with the oldest stage representing some of the most severely P-impoverishedsoils found in any terrestrial ecosystem. The richness of AMF operationaltaxonomic units was low on young (1000?s of years), moderately P-rich soils, greatest on relatively old (~120 000 years) low-P soils, and low again on the oldest (>2 000 000 years) soils that were lowest in P availability. A similar decline in AMF phylogenetic diversity on the oldest soils occurred, despite invariant host plant diversity and only small declines in host cover along the chronosequence. Differences in AMF community composition were greatest between the youngest and the two oldest soils, and this was best explained by differences in soil P concentrations. Our results point to a threshold in soil P availability during ecosystem regression below which AMF diversity declines, suggesting environmental filtering of AMF insufficiently adapted to extremely low P availability.

N-β-alanyldopamine metabolism, locomotor activity and sleep in Drosophila melanogaster ebony and tan mutants Rossi, Fabiana Alejandra; Bochicchio, Pablo Alejandro; Quesada Allue, Luis Alberto; Pérez, Martín Mariano Drosophila melanogaster Meigen mutants for N-β-alanyldopamine (NBAD) metabolism have altered levels of NBAD, dopamine and other neurotransmitters. The ebony1 mutant strain has very low levels of NBAD and higher levels of dopamine, whereas the opposite situation is observed in the tan1 mutant. Dopamine is implicated in the control of movement, memory and arousal, as well as in the regulation of sleep and wakefulness in D. melanogaster. N-β-alanyldopamine, which is best known as a cuticle cross-linking agent, is also present in nervous tissue and has been proposed to promote locomotor activity in this fly. The daily locomotor activity and the sleep patterns of ebony1 and tan1 mutants are analyzed, and are compared with wild-type flies. The tan1 mutant shows reduced locomotor activity, whereas ebony1 shows higher levels of activity than wild-type flies, suggesting that NBAD does not promote locomotor activity. Both mutants spend less time asleep than wild-type flies during night-time; ebony shows more consolidated activity during night-time and increased sleep latency, whereas tan is unable to consolidate locomotor activity and sleep in either phase of the day. The daily level of NBAD-synthase activity is measured in vitro using wild-type and tan1 protein extracts, and the lowest NBAD synthesis is observed at the time of higher locomotor activity. The abnormalities in several parameters of the waking/sleep cycle indicate some dysfunction in the processes that regulates these behaviours in both mutants.

Efecto de vecino: el poder de Brasil sobre el regionalismo de Argentina; The neighbouring effect: the power of Brazil over Argentinian regionalism Miranda, Roberto Alfredo El objetivo de este trabajo es analizar las características de la relación de Argentina con Brasil, a fin de determinar el efecto que este bilateralismo le provocó a su política exterior. El análisis, centrado en la primera década del presente siglo, tiene como eje las consecuencias de la situación de dependencia comercial de Argentina con Brasil. Sobre esta situación sostenemos que para Argentina tuvo un costo político significativo. Para desarrollar esta perspectiva pasamos revista a las relaciones bilaterales entre ambos países, fundamentalmente en lo concerniente a las coincidencias y divergencias que tuvieron en torno al Mercosur. Al mismo tiempo consideramos, como por un lado, las implicancias del liderazgo brasileño, y por el otro, las alternativas de política exterior que manejó Argentina para tratar el vínculo con su vecino desde un lugar diferente. Entre las conclusiones a las que arribamos, destacamos que la dependencia comercial con Brasil empujó a Argentina a secundar políticamente a su vecino en la estructuración de la integración sudamericana.; The purpose of this paper is to analyse the characteristics of the relation between Argentina and Brazil in order to determine the effect that this bilateralism provoked to its foreign policy. The analysis, centred in the first decade of this century, focuses on the consequences of the commercial dependence that Argentina has with Brazil. Concerning this situation we believe that Argentina had a significant political cost. In order to develop this point of view we go through the bilateral relations between both countries, especially in what is concerned with the coincidences and divergences that they have as regards Mercosur. At the same time we consider on one hand the implications of Brazilian leadership and on the other the alternatives of foreign policy that Argentina implemented to deal with her neighbour from a different place. Among the conclusions we arrived to, we highlight the commercial dependence with Brazil that led Argentina to follow its neighbour model in the building of South American integration.

Non est porro tuum uno sensu solum oculorum moueri: consolatio y visibilidad en las cartas de Cicerón a Marcelo; Non est porro tuum uno sensu solum oculorum moueri: consolatio and visibility in Ciceroʹs letters to Marcellus Correa, Soledad Este artículo pretende mostrar la forma estratégica en que usó Cicerón la carta de consuelo para ganar visibilidad y proteger su imagen durante un período crítico de su vida política. Como la renuencia de Marcelo a aceptar la clementia de César pone en riesgo esta estrategia, Cicerón activará la dimensión exhortativa del discurso de consuelo con la intención de negociar su propia imagen social y su rumbo de acción en comparación con la de su destinatario.; This article seeks to show how Cicero strategically used the consolatory letter in order to gain visibility and save his face during a critical period of his political life. As Marcellus reluctance to accept Caesar’s clementia places this strategy in jeopardy, Cicero will activate the exhortative dimension of consolatory discourse in order to nego‐ tiate his own social image and his course of action in comparison with his addressee’s.; Este artigo pretende mostrar como Cícero usou estrategicamente a carta de consolação para ganhar visibilidade e salvar a face durante um período crítico da sua vida política. Como a relutância de Marcelo em aceitar a clementia de César coloca esta estratégia em perigo, Cícero ativará a dimensão exortativa do discurso de consolação com vista a negociar a sua própria imagem social e o seu curso de ação em comparação com a do seu destinatário.; Cet article prétend montrer comment Cicéron a stratégiquement utilisé la lettre de consolation pour gagner de la visibilité et sauver la face durant une période critique de sa vie politique. Comme le doute de Marcellus à accepter la clementia de César met cette stratégie en danger, Cicéron activera la dimension exhortative du discours de consolation, dans le but de négocier sa propre image sociale et son discours d’action, en comparaison avec celui de son destinataire.

Salud percibida y rendimiento académico en adolescentes de escuelas públicas de la ciudad de Córdoba; Perceived health and academic performance among adolescents from public schools in the city of Córdoba Vitale, Romina; Degoy, Emilse; Berra, Silvina del Valle Introducción: El desempeño en la escuela podría estar vinculado a la salud en la adolescencia, y los logros educativos en esta edad pueden influir en la vida futura. El objetivo fue estudiar la asociación entre el rendimiento académico y la salud percibida en adolescentes, teniendo en cuenta las características sociodemográficas de sus familias. Población y métodos: Estudio piloto transversal en una muestra de adolescentes asistentes al ciclo básico de tres escuelas secundarias públicas de la ciudad de Córdoba, Argentina. El rendimiento académico se computó como el promedio de las calificaciones en todas las asignaturas y se consideró suficiente cuando fue igual a 6 puntos o mayor. La salud percibida se valoró con el cuestionario KIDSCREEN-52, que produce puntuaciones en diez dimensiones. Además, se recogió la edad, el sexo, el nivel de escolaridad materna, el nivel socioeconómico y la composición de la familia. Se realizaron análisis univariados, bivariados y modelos multivariados de regresión logística. Resultados: Participaron 554 adolescentes, 52% de los cuales eran mujeres. El rendimiento académico insuficiente (27,6%) fue más frecuente en los adolescentes que manifestaron peor relación con los padres (OR 2,68; IC 95%: 1,22- 5,85) y mejor relación con amigos (OR 0,46; IC 95%: 0,26-0,82). Hubo diferencias al estratificar por nivel socioeconómico: en el nivel alto, el rendimiento insuficiente fue más frecuente en adolescentes con percepción de menor autonomía y, en el nivel medio-bajo, en adolescentes con peor percepción del entorno escolar. Conclusión: El rendimiento académico se asoció a dimensiones psicosociales de la salud, como sus relaciones familiares, con amigos, autonomía y entorno escolar.

Expression of conditioned preference for low-quality food in sheep is modulated by foraging cost Catanese, Francisco Hernan; Distel, Roberto Alejandro; Villalba, Juan Jose Past positive experiences can increase herbivores’ motivation to eat low-quality foods. However, this is not always translated into a higher preference for low-quality foods in choice tests among foods of higher nutritional quality. Foraging behavior is also affected by properties of the feeding context because the quality and abundance of foods in nature change in time and space. We hypothesized that in a choice situation, the expression of a past positive experience with a low-quality food is modulated by the costs associated with selecting a high-quality food option. A total of 24 sheep were randomly assigned into two groups (n = 12). During conditioning phase, one group (CS+; i.e., conditioned group) was fed with oat hay (a low-quality food) for 20 min and immediately after a ration of soybean meal (a nutritious food), whereas the other group was also fed with oat hay but the offer of soybean meal was delayed 5 h (CS−; i.e., control group). After conditioning, we assessed sheep motivation to eat the oat hay in an experimental arena in which accessibility to alfalfa hay (a high-quality food) was increasingly restricted. When alfalfa hay was readily accessible, CS+ and CS− sheep almost exclusively selected this food, showing a small and similar preference for oat hay. However, when accessibility to alfalfa hay decreased, intake and selection of oat hay was greater in the CS+ sheep than in the CS− sheep. The latter was a consequence of differential changes in behavior between groups; for example, sheep in CS+ spent more time foraging oat hay and were more likely to switch to oat hay if they had previously been eating alfalfa hay than sheep in CS−. Our results show that behavioral expression of the conditioned preference for a low-quality food depends on parameters of the feeding context (e.g., availability). We suggest that this can be the link between learning models and optimal foraging models of diet selection.

Sol gel hybrid coatings with strontium-doped 45S5 glass particles for enhancing the performance of stainless steel implants: Electrochemical, bioactive and in vivo response Omar, Sheila Ayelén; Repp, Felix; Desimone, Paula Mariela; Weinkamer, Richard; Wagermaier, Wolfgang; Ceré, Silvia; Ballarre, Josefina The protection of stainless-steel implants by applying a hybrid organic–inorganic coating generates a barrier for ion migration and a potential holder for functional particles. Chemical composition of bioactive silicate-glasses (BG) can be varied to tailor their rate of dissolution in the biological environment. The substitution of calcium by strontium (Sr) generates a locally-controlled release of Sr-ions to the media. Strontium is known to reduce bone resorption and stimulate bone formation. This work presents coatings made by sol–gel method containing tetraethoxysilane, methyl-triethoxysilane and silica nanoparticles as precursors, and functionalized either with BG or Sr-substituted BG particles onto surgical grade stainless steel. The coated implants were tested in vitro for corrosion resistance and bioactivity, and in vivo to analyze bone formation. The applied coating system provided an excellent protection to aggressive fluids, even after 30 days of immersion. The presence of hydroxyapatite is shown as a first evidence of bioactivity. The evaluation of in vivo tests in Wistar–Hokkaido rat femur 4 or 8 weeks after the implantation showed slight differences in the thickness of newly formed bone measured by ESEM, and remarkable changes in bone quality characterized with Raman microscopy. The in vivo response of the coatings containing Sr-substituted bioglass is better at early times of implantation as regards the bone morphology and quality making this functionalized coatings a very promising option for implant protection and bone regeneration.

Contaminants in the southern tip of South America: Analysis of organochlorine compounds in feathers of avian scavengers from Argentinean Patagonia Martínez López, Emma; Espín, Silvia; Barbar, Facundo; Lambertucci, Sergio Agustin; Gómez Ramírez, Pilar; García Fernández, A. J. The aim of this study was to assess the exposure to organochlorine compounds (OC) in 91 primary wing feathers of avian scavengers, Turkey vulture (Cathartes aura), American black vulture (Coragyps atratus) and Southern crested caracaras (Polyborus plancus) from the southern tip of South America, in the Argentinean Patagonia. We analyzed for a series of OC including hexachlorocyclohexane (HCH) isomers, endosulfan, aldrin, dieldrin, endrin, dichlorodiphenyltrichloroethane (p,p’-DDT), dichlorodiphenyldichloroethane (p,p’-DDD), dichlorodiphenyldichloroethylene (p,p’-DDE), heptachlor and heptachlor-epoxide. This is the first study on OC in feathers of three terrestrial top carnivores from South America. OC concentrations found in the studied species were much higher than those found in feathers of raptors from Europe and Asia, which likely indicate their high use in the region, specifically in agriculture, and other possible uses of OC in this area. ∑HCH had the highest median concentration, followed by ∑Drins, ∑DDT, ∑Heptachlor, and ∑Endosulfan, similar to those reported in several food samples in Argentina. On the other hand, differences in OC profiles between species and areas may be related to feeding and migratory habits, as well as the molt period. Three individuals showed ∑DDT (DDT, DDD and DDE) concentrations in feathers related to sublethal effects. However, this comparison should be used with caution due to problems with extrapolating such data across tissues and species.