Spatiotemporal Variations in Abundance and Biomass of Planktonic Ciliates Related to Environmental Variables in a Temporal Pond, Argentina Kuppers, Gabriela Cristina; Claps, Maria Cristina This report describes the structure and seasonal dynamics of ciliated protozoa associated with variations in the physicochemical characteristics of the environment in a temporary pond in the Buenos Aires province, Argentina. Plankton samples were obtained and physicochemical variables measured monthly for two years. A total of 50 planktonic ciliates were recorded. The highest species richness occurred during the pond´s filling and stable-hydric phases. Upon the pond´s desiccation, the number of ciliate species decreased, with the lowest values being recorded in spring; while the highest abundance and biomass were observed before the droughts. Ciliate diversity tended to be higher after droughts but decreased with pond desiccation. Most of the ciliate species were rare and found during the filling periods. Vorticella convallaria, Pelagostrobilidium wilberti, and Coleps hirtus were dominant; Cyclidium glaucoma, Strobilidium caudatum, Pseudochilodonopsis piscatoris, Limnostrombidium viride, L. pelagicum, and Chilodonella sp. were common; and Pelagostrombidium mirabile along with Rhabdostyla sp.?an epibiont on cladocerans?were occasional. The first and the sum of all axes in canonical correspondence analysis explained a significant portion of the ciliate-data variance. The autumn and winter samples grouped together corresponding to the highest conductivities, high precipitations, and low temperatures?properties characterizing the filling and stable-hydric periods. The species were distributed mainly according to conductivity and temperature gradients along the first canonical axis. The structure and temporal dynamics of planktonic ciliates from this temporary pond varied with the changes in physicochemical characteristics of the environment determined by flooding and desiccation.

Gestión del multilingüismo y docencia indígena para una educación intercultural bilingüe en la Argentina; Gestão do multilinguismo e docência indígena para uma educação intercultural na Argentina; Management of multilingualism and indigene teaching for an intercultural bilingual education in Argentina Unamuno, Virginia El presente trabajo muestra los primeros resultados de una investigación sociolingüística en curso sobre la de educación intercultural bilingüe (EIB) en Argentina. El interés final de este trabajo es identificar algunos elementos que permitan dar cuenta del rol de las lenguas en los procesos sociales que involucran a la población indígena, poniendo en evidencia las formas en que los usos lingüísticos participan en la lucha por recursos materiales así como las representaciones sociales e ideologías lingüísticas que participan en la distribución desigual de dichos recursos entre grupos y al mantenimiento de desigualdades sociales. Para ello, se analiza el caso de una población – que llamamos El Algarrobo – en donde se forman docentes indígenas, los cuales son incorporados paulatinamente en las escuelas de la zona. En esta incorporación las instituciones educativas definen los roles de los docentes indígenas, así como el lugar de las lenguas en las mismas. Según muestra este trabajo, esta gestión de las lenguas está ligada a procesos de lucha social en los cuales las lenguas tienen un rol clave. La concepción del bilingüismo, las evaluaciones sobre las competencias lingüísticas de estudiantes y docentes indígenas, y las prácticas lingüísticas en las aulas ponen en evidencia la distancia entre los significados que circulan en los discursos oficiales sobre la EIB en Argentina y el sentido que obtienen éstos en las prácticas concretas en las aulas.; O presente trabalho expõe os primeiros resultados de uma pesquisa sociolinguística a respeito da Educação Intercultural bilíngue (EIB) na Argentina. O interesse final deste trabalho é identificar alguns elementos que permitem compreender o papel das línguas nos processos sociais que envolvem a população indígena, pondo em evidencia as formas pelas quais os usos linguísticos participam na luta por recursos materiais e as representações sociais e ideologias linguísticas funcionais, em uma distribuição desigual desses recursos entre os grupos, colaborando para a manutenção de desigualdades sociais. Para tanto, se analisa o caso de uma população – que chamamos El Algarrobo – onde se formam docentes indígenas, os quais são incorporados paulatinamente nas escolas da região. Nesta incorporação, as instituições educativas, definem os papeis dos docentes indígenas, assim como o lugar das línguas nessas mesmas instituições. Assim, este trabalho mostra que a gestão das línguas está ligada a processos de luta social nos quais as línguas têm um papel chave. A concepção de bilinguismo, as avaliações acerca das competências linguísticas dos estudantes e docentes indígenas, assim como as práticas linguísticas nas aulas, revelam a distância entre os significados que circulam nos discursos sociais a respeito da IEB na Argentina e o sentido que estes ganham nas práticas concretas em sala de aula.; Current paper presents the first outcome of an ongoing sociolinguistic research on bilingual intercultural education (EIB) in Argentina. The aim of this study is to identify some elements for an account of the role of language in the social process that involves native people by highlighting the manner in which language usage participate in the struggle for material resources and how social representations and linguistic ideologies are involved in the unequal distribution of resources among indigene groups and in the maintenance of social inequalities. The case of a population that called El Algarrobo has been analyzed. Native young people are trained as teachers and gradually incorporated in schools of the region. In such a process the educational institutions define the roles for native teachers and the place of languages. Results show that the management of languages is linked to the process of social struggle where languages have a key role. The conception of bilingualism, the assessments of native teachers with a competence of Spanish and classroom language practices evidence the distance between meanings in official discourses on EIB in Argentina and the meaning EIB has in day-to-day practice in the classroom and in the school.

Le "mouvement chalcédonien": opposition ecclésiastique et aristocratique sous le règne d'Alexis Ier Comnène (1081-1094) Casamiquela Gerhold, Victoria Errain Le « mouvement chalcédonien » fut un mouvement de contestation ecclésiastique dirigé par Léon, évêque de Chalcédoine, sous le règne d´Alexis Ier Comnène. Les revendications des ecclésiastiques rebelles étaient surtout de caractère ecclésiologique, mais ils établirent une alliance circonstancielle avec la haute aristocratie mécontente du régime d´Alexis Ier. Nous analyserons dans cet article les caractéristiques de cette alliance et son rôle politique dans la consolidation de la dynastie comnénienne.; The «Chalcedonian movement» was a movement of ecclesiastical opposition led by Leo, bishop of Chalcedon, during the reign of Alexios I Komnenos. Even if the demands of the bishops were mainly ecclesiological, they established a circumstantial alliance with the dissatisfied aristocracy of Alexios’ reign. We shall examine in this article the characteristics of that alliance, as well as its political role in the consolidation of the Comnenian dynasty.

Review of the Genus Andropogon (Poaceae: Andropogoneae) in America Based on Cytogenetic Studies Nagahama, Nicolas; Norrmann, Guillermo Alberto Andropogon is a pantropical grass genus comprising 100–120 species and found mainly in the grasslands of Africa and the Americas. In the new world the genus is represented by approximately sixty (diploids or hexaploids) species grouped in three sections. The hexaploid condition occurs only in the Americas and the full process of this origin is still uncertain, although cytogenetic analysis coupled with taxonomic evidence have provided strong support for new hypothesis. Stebbins proposed the first hypothesis suggesting that the origin of polyploidy in species of Andropogon in North America resulted from duplication of the genome of some diploid species, and then by intergeneric crosses with species of a related genus. Since then, numerous studies were performed to clarify the evolutionary history of the genus in America. In this paper, we present a review of cytogenetic studies in the American Andropogon species during the last four decades.

A DR4:tBID axis drives the p53 apoptotic response by promoting oligomerization of poised BAX Henry, Ryan E; Andrysik, Zdenek; Paris, Ramiro; Galbraith, Matthew D.; Espinosa, Joaquín M. The cellular response to p53 activation varies greatly in a stimulus‐ and cell type‐specific manner. Dissecting the molecular mechanisms defining these cell fate choices will assist the development of effective p53‐based cancer therapies and also illuminate fundamental processes by which gene networks control cellular behaviour. Using an experimental system wherein stimulus‐specific p53 responses are elicited by non‐genotoxic versus genotoxic agents, we discovered a novel mechanism that determines whether cells undergo proliferation arrest or cell death. Strikingly, we observe that key mediators of cell‐cycle arrest (p21, 14‐3‐3σ) and apoptosis (PUMA, BAX) are equally activated regardless of outcome. In fact, arresting cells display strong translocation of PUMA and BAX to the mitochondria, yet fail to release cytochrome C or activate caspases. Surprisingly, the key differential events in apoptotic cells are p53‐dependent activation of the DR4 death receptor pathway, caspase 8‐mediated cleavage of BID, and BID‐dependent activation of poised BAX at the mitochondria. These results reveal a previously unappreciated role for DR4 and the extrinsic apoptotic pathway in cell fate choice following p53 activation.

Energy dissipation channels in the adsorption of N on Ag(111) Martin Gondre, L.; Bocan, Gisela Anahí; Alducin, M.; Juaristi, J. I.; Díez Muiño, R. We theoretically study the competition between different energy dissipation channels in the adsorption of N atoms on Ag(1 1 1) surfaces. The three-dimensional potential energy surface that describes the interaction between the N atoms and the metal surface is built from density functional theory calculations. Classical dynamics simulations are subsequently performed to evaluate the adsorption probabilities. The contribution of electron?hole pairs excited in the surface during the adsorption process is included in the simulation by an electronic friction coefficient. Phonon excitations are also considered through the Generalized Langevin Oscillator model. We show that the role of the two channels during the adsorption dynamics is very different: phonons are responsible for determining the adsorption probability but electronic excitations are relevant at a later stage to fix the N atoms to the adsorption positions. We conclude that a theoretical model that intrinsically combines both energy dissipation channels is necessary to properly describe the full dynamics of the process.

Catolicismos, nacionalismos y comunitarismos en política social. Redes católicas en la creación del Ministerio de Bienestar Social de Argentina (1966-1970) Giorgi, Guido Ignacio; Mallimaci, Fortunato Horacio El presente artículo se propone estudiar los vínculos entre religión y política en general, y entre diversos grupos católicos y el Estado en particular, analizando la convergencia de distintas corrientes católicas, nacionalistas y comunitaristas durante el gobierno cívico-militar-religioso del Gral. Onganía en la Argentina (1966-1970). Veremos cómo la innovación institucional que constituye la creación del Ministerio de Bienestar Social dio lugar no solo a disputas por el control de los cargos de gobierno, sino también por la definición del rumbo de las políticas sociales. Recurriremos a la perspectiva de redes para identificar los distintos grupos socio-religiosos en los que estaban insertos los altos funcionarios de dicho gobierno; así como al análisis de documentos oficiales para dar cuenta de las concepciones comunitaristas de los actores. Esto nos permitirá probar la hipótesis de que el proyecto corporativista de la dictadura de Onganía habría tenido en el Ministerio de Bienestar Social uno de los intentos más claros de crear una sociedad comunitarista.

Tarsal Organ Morphology and the Phylogeny of Goblin Spiders (Araneae, Oonopidae), with Notes on Basal Genera Platnick, Norman I.; Abrahim, Naiara; Álvarez Padilla, Fernando; Andriamalala, Daniela; Baehr, Barbara; Baert, Léon; Bonaldo, Alexandre; Brescovit, Antonio; Chousou Polydouri, Natalia; Dupérré, Nadine; Eichenberger, Beata; Fannes, Wouter; Gaublomme, Eva; Gillespie, Rosemary; Grismado, Cristian José; Griswold, Charles; Harvey, Mark; Henrard, Arnaud; Hormiga, Gustavo; Izquierdo, Matías Andres; Jocqué, Rudy; Kranz Baltensperger, Yvonne; Kropf, Christian; Ott, Ricardo; Ramirez, Martin Javier; Raven, Robert; Rheims, Cristina; Ruiz, Gustavo; Santos, Adalberto; Saucedo, Alma; Sierwald, Petra; Szuts, Tamás; Ubick, Darrell; Wang, Xin Ping Based on a survey of a wide variety of oonopid genera and outgroups, we hypothesize new synapomorphies uniting the Oonopidae (minus the South African genus Calculus Purcell, which is transferred to the Orsolobidae). The groundplan of the tarsal organ in Oonopidae is hypothe- sized to be an exposed organ with a distinctive, longitudinal ridge originating from the proximal end of the organ, and a serially dimorphic pattern of 4-4-3-3 raised receptors on legs I–IV, respec- tively. Such organs typify the diverse, basal, and ancient genus Orchestina Simon. Several other genera whose members resemble Orchestina in retaining two plesiomorphic features (an H-shaped, transverse eye arrangement and a heavily sclerotized, thick-walled sperm duct within the male palp) are united by having tarsal organs that are partly (in the case of Cortestina Knoflach) or fully capsulate (in the case of Sulsula Simon, Xiombarg Brignoli, and Unicorn Platnick and Brescovit). The remaining oonopids are united by the loss of the heavily sclerotized palpal sperm duct, pre- sumably reflecting a significant transformation in palpal mechanics. Within that large assemblage, a 4-4-3-3 tarsal organ receptor pattern and an H-shaped eye arrangement seem to be retained only in the New Zealand genus Kapitia Forster; the remaining genera are apparently united by a reduction in the tarsal organ pattern to 3-3-2-2 raised receptors on legs I–IV and by the acquisi- tion of a clumped eye arrangement. Three subfamilies of oonopids are recognized: Orchestininae Chamberlin and Ivie (containing only Orchestina; Ferchestina Saaristo and Marusik is placed as a junior synonym of Orchestina), Sulsulinae, new subfamily (containing Sulsula, Xiombarg, Unicorn, and Cortestina), and Oonopinae Simon (containing all the remaining genera, including those previously placed in the Gamasomorphinae). The type species of Sulsula and Kapitia, S. pauper (O. P.-Cambridge) and K. obscura Forster, are redescribed, and the female of S. pauper is described for the first time. A new sulsuline genus, Dalmasula, is established for Sulsula parvimana Simon and four new species from Namibia and South Africa.

He II lambda4686 in Eta Carinae: Collapse of the Wind-Wind Collision Region during Periastron Passage Teodoro, M.; Damineli, A.; Arias, J. I.; de Araújo, F. X.; Barba, Rodolfo Hector; Corcoran, Michael; Borges Fernandes, M.; Fernandez Lajus, Eduardo Eusebio; Fraga, L.; Gamen, Roberto Claudio; Gonzalez, Jorge Federico; Groh, J. H.; Marshall, J. L.; McGregor, P. J.; Morrell, N.; Nicholls, D. C.; Parkin, E. R.; Pereira, C. B.; Phillips, M. M.; Solivella, Gladys Rebeca; Steiner, J. E.; Stritzinger, M.; Thompson, I.; Torres, C. A. O.; Torres, M. A. P.; Zevallos Herencia, M. I. The periodic spectroscopic events in η Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have been proposed to explain the variations of different spectral features, such as an eclipse by the wind-wind collision (WWC) boundary, a shell ejection from the primary star or accretion of its wind onto the secondary. All of them have problems explaining all the observed phenomena. To better understand the nature of the cyclic events, we performed a dense monitoring of η Carinae with five Southern telescopes during the 2009 low-excitation event, resulting in a set of data of unprecedented quality and sampling. The intrinsic luminosity of the He II λ4686 emission line (L 310 L) just before periastron reveals the presence of a very luminous transient source of extreme UV radiation emitted in the WWC region. Clumps in the primary's wind probably explain the flare-like behavior of both the X-ray and He II λ4686 light curves. After a short-lived minimum, He II λ4686 emission rises again to a new maximum, when X-rays are still absent or very weak. We interpret this as a collapse of the WWC onto the "surface" of the secondary star, switching off the hard X-ray source and diminishing the WWC shock cone. The recovery from this state is controlled by the momentum balance between the secondary's wind and the clumps in the primary's wind.

Alternatives to free molecular halogens as chemoselective reactants: Catalysis of organic reactions with reusable complexes of halogen metal salts Rossi, Laura Isabel; Velasco, Manuel Isaac Organometallic complexes of halogen metallic salts have been used as catalysts in different organic reactions, mainly the oxidation of organic compounds. Their use has not only allowed the reduction of the amounts of catalyst (since they can be reused) but also a lower generation of by-products and wastes. The different reaction media developed through the research were analyzed by several green parameters and the best results were obtained with complexes that have cyclodextrins as organic ligands. The proposed methodology is an alternative to use of molecular halogen as oxidant or catalyst when halogens are significant chemoselective reactants.

Influence of microbial community composition and metabolism on air−sea ΔpCO2 variation off the western Antarctic Peninsula Moreau, Sébastien; Schloss, Irene Ruth; Mostajir, Behzad; Demers, Serge; Almandoz, Gaston Osvaldo; Ferrario, Martha Elba; Ferreyra, Gustavo Adolfo We studied CO 2 and O 2 dynamics in the western Antarctic Peninsula (WAP) waters in relation to (1) phytoplankton biomass, (2) microbial community primary production and respiration, and (3), for the first time, phytoplankton composition, during summer and fall in 3 consecutive years (2002, 2003 and 2004). The areal average of δpCO 2 (the difference between surface seawater and atmospheric partial pressure of CO 2) for the 3 yr was significantly negative (.20.04 ± 44.3 μatm, p < 0.01) during the summer to fall period in the region, possibly indicating a CO 2 sink. In the southern WAP (i.e. south of Anvers Island), δpCO 2 was significantly negative (.43.60 ± 39.06 μatm) during fall. In the northern WAP (north of Anvers Island), δpCO 2 values showed a more complex distribution during summer and fall (.4.96 ± 37.6 and 21.71 ± 22.39 μatm, respectively). Chlorophyll a (chl a) concentration averaged 1.03 ± 0.25 μg l.1 and was higher in the south of the peninsula. Phytoplankton composition influenced chl a concentration with higher and lower values for diatom-and phytoflagellate-dominated communities, respectively. A significant negative correlation existed between chl a and δpCO 2. From incubation experiments performed in the northern WAP, respiration was low (averaging 5.1 mmol O 2 m.3 d.1), and the net community production (NCP) correlated negatively with δpCO 2 and positively with %O 2 saturation. However, despite the high NCP values measured, δpCO 2 was significantly positive in the northern WAP during the summer to fall period. Strong mixing and lower chl a concentration may explain this result. In contrast, δpCO 2 was significantly negative in the southern WAP, possibly because of high surface water chl a concentration.

Utilidad de las respuestas rápidas de estrés para evaluar la evolución del tratamiento en un canino con fobia social; Use of the stress fast response for the evaluation of a social phobia treatment in a dog Cainzos, Romina Paola; Koscinczuk, Patricia; Rossner, Maria Victoria; Alabarcez, Maria Nieves; Maurenzig, Nelson Damian El miedo es un estado emocional aversi­vo ante una amenaza real o percibida como peligro externo. Esta emoción produce respuestas autonómicas que alteran la homeostasis del individuo. Cuando esta situación se prolonga en el tiempo, el estado de salud se afecta. El objetivo de este trabajo fue relacionar el reflejo pupilar y las frecuencia cardíaca y respiratoria con la producción de saliva, concentración de cortisol y respuestas conductuales, para evaluar la evolución del tratamiento con paroxetina (1 mg/kg cada 12 horas) y terapia conductual en una perra boxer con fobia social, en el primer mes post adopción. Ambas frecuencias se mantuvieron normales durante toda la experiencia (FC 76 a 98 lpm y FR 18 a 40 mrm). Sin embargo, en el día 1 la frecuencia cardíaca fue más alta que en los días 15 y 30 (p<0,05). Con respecto a la dilatación pupilar, en el día uno se observó midria­sis y a partir del día 15 el reflejo pupilar fue normal. Si bien la producción de saliva fue más abundante en el primer día que en los días 15 y 30 (p<0,05), las concentraciones de cortisol durante todo el periodo no arrojaron diferencias significativas, presentando el valor absoluto más alto el día 15 (1,22 μg/dl). Tanto las variables para los comportamientos de mantenimien­to como para los comportamientos sociales fueron significativamente diferentes a lo largo de la experiencia (p<0,001). Por otra parte, no se presentaron efectos adversos atribuibles a la paroxetina y la paciente recuperó el apetito, entrando en celo a los dos meses después. Los parámetros clínicos asociados al sistema nervioso autónomo resultan de interés práctico para evaluar la progresión del tratamiento del paciente canino con fobia.; Fear is an aversive state emotion to a real or perceived threat external situation. This emotion induces autonomic responses that alter homeostasis. When this situation is prolonged in time, health is affected. Aim of this work was to establish a relationship among routine clinical parameters -such as hearth and breath rates, pupil reflect with salivary production, salivary cortisol and behaviour response- for the evaluation of treatment evolution with paroxetin (1 mg/kg every 12 hours) associated to a behavioural therapy in a boxer bitch with social phobia, during the first month after adoption. Both heart and breath rates were between the normal range for the species during all the experiment (76 to 98 bpm and 18 to 40 bpm respectively. Regarding pupil dilation, on the first day the patient had mydriasis, but since day 15 she had myosis. Saliva production was more abundant on the first day, compared to days 15 and 30 (p<0.05); salivary cortisol did not show significant differences, with the highest absolute value on day 15 (1.22 µg/ml). Variables of both maintenance and social behaviours were significatively different during the entire assay (p<0.001). On the other hand, there was no adverse effect associated to paroxetin and the patient recovered the appetite, presenting heat during the second month. Clinical parameters associated with the autonomic nervous system result of practical interest to evaluate the treatment evolution of a phobic patient.

El Concilio Vaticano II y su impacto en el campo episcopal argentino; The Second Vatican Council and its impact on argentinian Episcopal field Margaria, Paulo Román El presente artículo busca explorar el impacto que tuvo el Concilio Vaticano II en la Iglesia Católica Argentina, haciendo especial hincapié en el campo de los obispos, desde una perspectiva socio-religiosa que pretende dar cuenta de la complejidad del campo católico. Para ello nos parece adecuado utilizar la noción de "campo" en términos bourdianos. Consideramos que hablar de "campo religioso" nos permite concebir el catolicismo como un espacio social dinámico y atravesado por constantes conflictos y luchas llevadas a cabo por grupos de agentes que intentan dominar dicho campo. Esto nos permitirá caracterizar las diversas posturas que el Concilio acentuará en el catolicismo argentino, actuando de este modo como un propulsor y legitimador de posiciones y conflictos que existían previamente.; This article examines the impact that Second Vatican Council had on argentinian Catholic Church, with special emphasis on the Bishops field, from a socio-religious perspective that seeks to explain the complexity of Catholic field. Therefore, it seems appropriate to use the Pierre Bourdieu’s notion of "field". We believe that talk about "religious field" allows us to conceive Catholicism as a dynamic social space spanned by constant conflicts and struggles carried out by groups of agents who tried to dominate the field. Again, this allows us to characterize the positions that the Council emphasized in the Argentine Catholicism, acting as a propellant and legitimizing ideas and conflicts that existed previously.

Wind-induced damage in two regions of Argentina Natalini, Bruno; Lassig, Jorge Luis; Natalini, Mario Bruno; Palese, Claudia Information on wind-induced damage to civil structures in Argentina is scarce. In this paper, general trends regarding both meteorological conditions and patterns of damage when damage occurred in two regions of Argentina are presented. The regions under study were the north-east of Argentina (NEA) and the north-Patagonia. This research is based on a collection of data comprising field surveys conducted after the passage of destructive storms, NCEP/NCAR Reanalysis, a Global Data Assimilation System model and other secondary sources like emergency services, local press, local councils and the National Weather Service. It is shown that both regions have similar problems of vulnerability, even though they have different meteorological environments. Topics that must be addressed to reduce the vulnerability of civil structures have been identified.

Cross-neutralization of the coagulant activity of Crotalus durissus terrificus venom from the northeast of Argentina by bivalent bothropic antivenom Rodríguez, Juan Pablo; Gay, Claudia Carolina; Fusco, Luciano Sebastian; Gauna Pereira, María del Carmen; Acosta, Ofelia Cristina; Leiva, Laura Cristina Ana Cross-neutralization of Crotalus durissus terrificus venom coagulant activity was tested using bivalent horse antivenom against Bothrops alternatus and Bothrops diporus venoms. Our in vitro and in vivo experiments showed that bothropic antivenom neutralizes the thrombin-like activity of crotalic snake venom and this cross-reaction was demonstrated by immunoassays either with whole venom or a purified thrombin-like enzyme. These results suggest common antigenic properties and, consequently, similar molecular structure among venom thrombin-like enzymes. Besides, they provide information that could be further used in the development of new antivenom formulations.

Ultra-sensitive electrochemical immunosensor using analyte peptidomimetics selected from phage display peptide libraries Arevalo, Fernando Javier; González Techera, Andrés; Zon, María Alicia; González Sapienza, Gualberto; Fernández, Héctor Immunosensors for small analytes have been a great addition to the analytical toolbox due to their high sensitivity and extended analytical range. In these systems the analyte is detected when it competes for binding to the detecting antibody with a tracer compound. In this work we introduce the use of phage particles bearing peptides that mimic the target analyte as surrogates for conventional tracers. As a proof of concept, we developed a magneto-electrochemical immunosensor (EI) for the herbicide molinate and compare its performance with conventional formats. Using the same anti-molinate antibody and phage particles bearing a molinate peptidomimetic, the EI performed with an IC 50 of 0.15ngmL -1 (linear range from 4.4×10 -3 to 10ngmL -1). Compared to the conventional ELISA, the EI was faster (minutes), performed with a much wider linear range, and the detection limit that was 2500-fold lower. The EI produced consistent measurements and could be successfully used to assay river water samples with excellent recoveries. By using the same EI with a conventional tracer, we found that an important contribution to the gain in sensitivity is due to the filamentous structure of the phage (9×1000nm) which works as a multienzymatic tracer, amplifying the competitive reaction. Since phage-borne peptidomimetics can be selected from phage display libraries in a straightforward systematic manner and their production is simple and inexpensive, they can contribute to facilitate the development of ultrasensitive biosensors.

Bioestratigrafía de conodontes del Darriwiliano medio (Ordovícico) de Argentina: La Formación Las Aguaditas, Precordillera Central; Biostratigraphy of Middle Darriwilian (Ordovician) conodonts from Argentina: Las Aguaditas Formation, Central Precordillera Heredia, Susana Emma Se recuperaron elementos del género Eoplacognathus de muestras de la Formación Las Aguaditas aflorante en el río de Las Chacritas, provincia de San Juan, Argentina. Estos depósitos de calizas oscuras son grainstones oscuros, packstones y wackestones y representan facies de rampa carbonática distal. Los conodontes guía Eoplacognathuspseudoplanus (Viira) y Eoplacognathus suecicus Bergström documentan las Zonas de E. pseudoplanus y de E. suecicus indicando una edad darriwiliana media para los niveles portadores de conodontes en la Formación Las Aguaditas. Se realiza una evaluación de los antecedentes sobre el registro fósil del género Eoplacognathus en la Precordillera Argentina. Por último, se propone el uso del esquema de biozonas de conodontes del Darriwiliano medio de Báltica para la Precordillera Argentina.; Several P elements of Eoplacognathus were recovered from samples collected in Las Aguaditas Formation, Las Chacritas river section, San Juan Province, Argentina. These dark grainstones, packstones, and wackestones represent distal carbonate rampfacies. The key conodonts Eoplacognathus pseudoplanus (Viira) and Eoplacognathus suecicus Bergström, document the Eoplacognathus pseudoplanus and the E. suecicus Zones pointing out middle Darriwilian age for the conodont–bearing strata in Las Aguaditas Formation. The species E. suecicus is recorded here for first time in the Argentine Precordillera. An evaluation of the record of this middle Darriwilian conodont genus in the Precordillera is presented here. Finally, the use of the middle Darriwilian Baltic conodont chart is proposed for the Argentine Precordillera.

Checklist and updated distribution of Protoneuridae from Brazil Pessacq, Pablo; Santos, Tatiana Chrysostomo; Costa, Janira Martins Protoneuridae are represented in the neotropics by 16 genera and 117 species, of which 64 species in 12 genera are known to occur in Brazil. Most of them are known only from the original descriptions or isolated records. During 2009 the Protoneuridae collection of MNRJ was revised; 2800 specimens were studied, belonging to 40 species in nine genera. As a result, the distribution of 25 species is extended, including 50 new records for several states and three new records for the country: Epipleoneura lamina Williamson, Protoneura woytkowskii Gloyd, and Psaironeura remissa (Calvert). The widest distributions are shown by Neoneura sylvatica Hagen in Selys, Epipleoneura venezuelensis Rácenis, and Epipleoneura metallica Rácenis, which are also recorded from the highest number of states: 11 and eight respectively.Additionally, the distribution of most species within previously recorded states is extended.

On the orientation of fibres in structural members fabricated with self compacting fibre reinforced concrete Zerbino, Raul Luis; Tobes, Juan Manuel; Bossio, Maria Eugenia; Giaccio, Graciela Marta The incorporation of fibres into concrete produces important benefits, mainly on the residual load-bearing capacity. These improvements depend on the type, content and orientation of the fibres, being a strong relationship between the number of fibres in the fracture surfaces and the post peak parameters. Although the fibres could be homogeneously distributed after mixing, the casting and compaction processes can significantly affect the fibre distribution and orientation, and consequently the mechanical performance of the material. In the case of Fibre Reinforced Self Compacting Concrete (FR-SCC) the existence of significant flow and wall effects may influence fibre orientation. This paper analyzes the fibre orientation in thin structural elements cast with FR-SCC and its effects on the residual mechanical properties. A slab of 0.90 × 1.80 × 0.09 m, a wall of 0.50 × 2.00 × 0.08 m, and a beam of 0.15 × 0.15 × 2.50 m were selected as representative elements where different concrete flow conditions take place. A strong heterogeneity in the orientation of the fibres was found. The fibre orientation varied with the flow rate and with the wall effect; the thickness of the elements or the proximity to the bottom of the moulds appeared as important variables. It was demonstrated that in thin elements the residual mechanical properties can be quite different when diverse zones and/or directions of the structural elements are considered. © 2011 Elsevier Ltd. All rights reserved.

Electrostatic self-assembly of hierarchical porous carbon microparticles Balach, Juan Manuel; Bruno, Mariano Martín; Cotella, Nelson Gustavo; Acevedo, Diego Fernando; Barbero, César Alfredo Hierarchical porous carbon microparticles (HPCMs) are produced by milling and sieving porous monolithic carbon, which was obtained by carbonization of a resorcinol-formaldehyde gel in the presence of surfactant as a pore stabilizer. The obtained HPCMs has a surface area of 536 m2 g-1 and maximum specific capacitance and areal capacitance, measured at slow scan rates, of 194 F g-1 and 152 mF cm-2 respectively. Moreover, the carbon surface remains accessible at 100 mV s-1 with large values of specific capacitance (154 F g-1) and areal capacitance (121 mF cm-2), making the material suitable for fast supercapacitors. The HPCMs are then built into electrostatic self-assembled (ESA) adsorbed layers by sequential immersion of a planar electrode in HPCMs dispersions and a cationic polyelectrolyte. Using soluble redox molecules, it is possible to detect the finite (inside the pores) and semi-infinite (outer surface) diffusion of redox species. The specific capacitance of the HPCMs could be increased up to 5 times (to ca. 900 F g-1 in acid media) by adsorption of naphthoquinone molecules on the carbon surface. Using the ESA process, it is possible to build a layer with three different quinones in a single electrode. The specific capacitance of those layers is more than 4 times higher and maintained nearly constant in a wide range of potential.