404 research outputs found

    Dynamic gating in the nucleus accumbens: Behavioral state-dependent synchrony with the prefrontal cortex and hippocampus

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    Contextual and sensory information, goals, and the motor plan to achieve them are integrated in the nucleus accumbens (NA). Although this integration needs flexibility to operate in a variety of environments, models of NA function rarely consider changing behavioral states. Here, intracellular recordings in anesthetized rats revealed rapid changes in the synchronization between NA up states and prefrontal cortical (PFC) local field potentials (LFPs). The synchronization of the NA with the PFC and ventral hippocampus also varied over time in awake rats, depending on the behavioral state of the animal: NA LFPs followed hippocampal theta rhythms during spatial exploration, but not during an operant task when they were instead synchronized with slower PFC rhythms. These data indicate that the ability of the NA to follow cortical inputs can rapidly change, allowing for a mechanism that could select an optimal response for a given behavioral condition

    The Media and Public Agendas. Testing for Media Effects in Argentina During 2003-2008

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    In this paper we examine the presence of agenda-setting effects by the print media in Argentina from June 2003 to December 2008. Using previously unavailable monthly data on newspapers mentions we test two hypotheses about the relationship between the different agendas. We find support for the hypothesis that there were media effects during our period of analysis. More specifically, we find that the total number of newspaper mentions of the President positively influenced public confidence in the government. Finally, there is also evidence of a strong and stable relationship between the total number of economic news and leading economic indicators.Agenda-setting, Public opinion, Cointegration, Media effects

    El Sistema Antártico

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    Fil: Gutiérrez Posse, Hortensia D. T.. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Internacional Público. Buenos Aires, ArgentinaFil: Gutiérrez Posse, Hortensia D. T. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Internacional Humanitario. Buenos Aires, ArgentinaFil: Alonso, Gabriela Liliana. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Breier, Ingrid E. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Cabrera Felisoni, Patricio O. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: González, Ariel W. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Jorquera, Mario. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Rizzo Alonso, Hermán G. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaEn el marco del ciclo profesional orientado se desarrolló durante 1989 un curso de actualización sobre el sistema antártico. Tenía por objetivo no sólo la profundización de los conocimientos sino también brindar la ocasión de que se ensayasen técnicas de investigación. Los trabajos que a continuación se publican reflejan resultados logrados por alumnos de ese curso. Ellos abordan distintos aspectos de una compleja cuestión que interesa directamente a nuestro país.\n\nPrólogo / Hortensia D. T. Gutiérrez Posse. El Sistema Antártico como régimen objetivo / Gabriela Liliana Alonso. Necesidad de su preservación para salvaguarda de la paz mundial / Ingrid E. Breier. Conservación y protección del medio ambiente antártico / Patricio O. Cabrera Felisoni. Los recursos minerales en el marco del Sistema Antártico : algunas reflexiones / Ariel Walter González. Evolución de los presupuestos jurídicos del Sistema Antártico / Mario Jorquera. Año 1991 y la soberanía en la Antártida, de condición a objetivo / Hernán G. Rizzo Alonso.\

    Differential Contribution of Subunit Interfaces to α 9 α 10 Nicotinic Acetylcholine Receptor Function

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    Nicotinic acetylcholine receptors can be assembled from either homomeric or heteromeric pentameric subunit combinations. At the interface of the extracellular domains of adjacent subunits lies the acetylcholine binding site, composed of a principal component provided by one subunit and a complementary component of the adjacent subunit. Compared with neuronal nicotinic acetylcholine cholinergic receptors (nAChRs) assembled from α and β subunits, the α9α10 receptor is an atypical member of the family. It is a heteromeric receptor composed only of α subunits. Whereas mammalian α9 subunits can form functional homomeric α9 receptors, α10 subunits do not generate functional channels when expressed heterologously. Hence, it has been proposed that α10 might serve as a structural subunit, much like a β subunit of heteromeric nAChRs, providing only complementary components to the agonist binding site. Here, we have made use of site-directed mutagenesis to examine the contribution of subunit interface domains to α9α10 receptors by a combination of electrophysiological and radioligand binding studies. Characterization of receptors containing Y190T mutations revealed unexpectedly that both α9 and α10 subunits equally contribute to the principal components of the α9α10 nAChR. In addition, we have shown that the introduction of a W55T mutation impairs receptor binding and function in the rat α9 subunit but not in the α10 subunit, indicating that the contribution of α9 and α10 subunits to complementary components of the ligand-binding site is nonequivalent. We conclude that this asymmetry, which is supported by molecular docking studies, results from adaptive amino acid changes acquired only during the evolution of mammalian α10 subunits.Fil: Boffi, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Marcovich, Irina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Gill Thind, JasKiran K.. University College London; Reino UnidoFil: Corradi, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Collins, Toby. University College London; Reino UnidoFil: Lipovsek, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Moglie, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Plazas, Paola Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Craig, Patricio Oliver. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Millar, Neil S.. University College London; Reino UnidoFil: Bouzat, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

    SCTP robusto a retransmisiones espúreas

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    El objetivo de este artículo es contribuir en los aspectos relacionados con la degradación de performance en los protocolos de transporte confiables, ante el fenómeno de congestión de las redes globales, en particular tomando como modelo de referencia SCTP (Stream Control Transmission Protocol). Al problema de la congestión se suman el reordenamiento de paquetes y el cambio brusco del round-trip-time, muy común en redes wireless. Estos comportamientos de la red subyacente producen una seria degradación de la performance de los protocolos de transporte . Se propone para SCTP un mecanismo adaptativo con el fin de disminuir la ocurrencia de los denominados falsos timeouts y falsos fast retransmits, que producen degradación en performance y la subutilización de recursos, principalmente de ancho de banda y buffers. La extensión del protocolo SCTP que incluimos la denominamos “RR-SCTP”.The objective of this paper is to contribute to the analysis of degradation of performance in realible transport protocols in the presence of global networks congestion assuming, as the reference model, the case of the SCTP (Stream Control Transmission Protocol). Beyond the question of congestion, this study addresses packages reordering and round-trip-time abrupt changes that are very common in wireless networks. With the current congestion control mechanisms, these underlying network behaviors significantly degrade the performance of the transport protocols. We propose an adaptive algorithm for the SCTP that will diminish the frequency of the “false timeouts” and the “false fast retransmits”. These issues both degrade performance and impede the maximum utilization of resources (principally, the bandwidth and the buffers).We call our SCTP protocol extension "RR-SCTP".I Workshop de Arquitecturas, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

    Asfixia perinatal asociada a la mortalidad neonatal temprana: estudio de población de los óbitos evitables

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    OBJECTIVE: To compare the epidemiological profile of avoidable early neonatal deaths associated with perinatal asphyxia according to region of death in the State of São Paulo, Brazil. METHODS: Population-based cohort study including 2,873 avoidable deaths up to six days of life associated with perinatal asphyxia from January 2001 to December 2003. Perinatal asphyxia was considered if intrauterine hypoxia, birth asphyxia, or meconium aspiration syndrome were written in any line of the original Death Certificate. Epidemiological data were also extracted from the Birth Certificate. RESULTS: During the three years, 1.71 deaths per 1,000 live births were associated with perinatal asphyxia, which corresponded to 22% of the early neonatal deaths. From the 2,873 avoidable deaths, 761 (27%) occurred in São Paulo city; 640 (22%), in the metropolitan region of São Paulo city; and 1,472 (51%), in the countryside of the state. In the first two regions, deaths were more frequent in public hospitals, among newborns with gestational age of 36 weeks or less, and among babies weighing less than 2500g. In the countryside, mortality was more frequent in philanthropic hospitals, in term newborns and in neonates weighing over 2500g. Most of these neonates were born during daytime in their hometown and died at the same institution in which they were born within the first 24 hours after delivery. Meconium aspiration syndrome was related to 18% of the deaths. CONCLUSIONS: Perinatal asphyxia is a frequent contributor to the avoidable early neonatal death in the state with the highest gross domestic product per capita in Brazil, and it shows the need for specific interventions with regionalized focus during labor and birth care.OBJETIVO: Comparar el perfil epidemiológico de los óbitos neonatales tempranos evitables asociados a la asfixia perinatal conforme a la región de ocurrencia del óbito en la provincia de São Paulo (Brasil). MÉTODOS: Cohorte de población constituida por 2.873 óbitos evitables hasta seis días de vida asociados a la asfixia perinatal ocurridos entre enero de 2001 y diciembre de 2003. Se consideró como asfixia perinatal la presencia de hipoxia intraútero, asfixia al nacer o síndrome de aspiración de meconio en cualquier línea de la Declaración de Óbito original. Variables epidemiológicas también fueron extraídas de las Declaraciones de Nacido Vivo. RESULTADOS: En el trienio, 1,71 muertes por 1.000 nacidos vivos estaban asociadas a la asfixia perinatal, correspondiendo al 22% de los óbitos neonatales tempranos. De los 2.873 óbitos evitables, 761 (27%) tuvieron lugar en São Paulo, capital; 640 (22%), en la región metropolitana de la capital; y 1.472 (51%) en el interior de la provincia. En las dos primeras regiones predominaron las muertes en hospitales públicos, recién nacidos con edad gestacional inferior a 37 semanas y peso inferior a 2.500g. En el interior, los óbitos fueron más frecuentes en entidades benéficas, recién nacidos a término y con peso superior a 2.500g. La mayoría de los bebés nació durante el día en el municipio de residencia materna y evolucionó a óbito en el hospital de nacimiento hasta 24 horas después del parto. El síndrome de aspiración de meconio estuvo presente en el 18% de los óbitos. CONCLUSIONES: La asfixia perinatal es un contribuyente frecuente a la muerte neonatal temprana evitable en la provincia con el más grande producto interno bruto per capita de Brasil, lo que evidencia la necesidad de intervenciones específicas con enfoque regionalizado en la asistencia al parto y al nacimiento.OBJETIVO: Comparar o perfil epidemiológico dos óbitos neonatais precoces evitáveis associados à asfixia perinatal conforme a região de ocorrência do óbito no Estado de São Paulo. MÉTODOS: Coorte populacional constituída por 2.873 óbitos evitáveis até seis dias de vida associados à asfixia perinatal ocorridos entre janeiro de 2001 e dezembro de 2003. Considerou-se como asfixia perinatal a presença de hipóxia intraútero, asfixia ao nascer ou síndrome de aspiração de mecônio em qualquer linha da Declaração de Óbito original. Variáveis epidemiológicas também foram extraídas das Declarações de Nascido Vivo. RESULTADOS: No triênio, 1,71 mortes por 1.000 nascidos vivos estavam associadas à asfixia perinatal, correspondendo a 22% dos óbitos neonatais precoces. Dos 2.873 óbitos evitáveis, 761 (27%) ocorreram em São Paulo, capital; 640 (22%), na região metropolitana da capital; e 1.472 (51%), no interior do estado. Nas duas primeiras regiões predominaram as mortes em hospitais públicos, recém-nascidos com idade gestacional inferior a 37 semanas e peso abaixo de 2500g. No interior, os óbitos foram mais frequentes em entidades beneficentes, recém-nascidos a termo e com peso superior a 2500g. A maioria dos bebês nasceu durante o dia no município de residência materna e evoluiu para óbito no hospital de nascimento até 24 horas após o parto. A síndrome de aspiração de mecônio esteve presente em 18% dos óbitos. CONCLUSÕES: A asfixia perinatal é um contribuinte frequente para a morte neonatal precoce evitável no estado com o maior produto interno bruto per capita do Brasil, evidenciando a necessidade de intervenções específicas com enfoque regionalizado na assistência ao parto e ao nascimento.UNIFESP-EPMFundação SEADE Divisão de Produção de Indicadores DemográficosFundação SEADEUNIFESP, EPMSciEL

    Saynete nuevo intitulado La Boda de don Patricio o Chistosa escena nocturna : para ocho personas

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    Mejoramiento del porcentaje de proteina en maiz para ensilaje con el aumento y parcializaci 3n de la fertilizacion nitrogenada

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    In clay soils with poor drainage two trials were carried out with the objective of determining the effect of nitrogen application on maize (Zea mays L.) for silage on forage yield and protein content. In Trial 1, the treatments were two corn silage hybrids of different growing periods, SX-43 and INIA-150, sown at 90.000 plants ha-1 and four N rates: 0, 100, 200 and 400 kg N ha-1. In Trial 2, the treatments were two N rates: 200 and 400 kg of N ha-1, and three forms of N application: a) 1/2 at sowing + 1/2 at 30 cm plant height; b) 1/3 at sowing + 1/3 at 30 cm plant height + 1/3 at 60 cm plant height; and c) 1/4 at sowing + 1/4 at 30 cm plant height + 1/4 at 60 cm plant height +1/4 at flowering. One treatment was without N. In Trial 1 N application increased DM yield (P < 0.05), but no significant response was observed with N rates between 100 and 400 kg N ha-1, due to soil limitations. Forage production and protein percentage increased significantly with N application. In Trial 2, DM production in corn silage increased with higher N rates (P < 0.05). Forage protein percentage was increased by higher N rates and partitioning of the application. On increasing the partitioning of N from two to four applications, protein percentage of forage was increased by 23 and 37% for 200 and 400 kg of N ha-1, respectively.En suelos arcillosos de mal drenaje se realizaron dos ensayos con el objetivo de determinar la respuesta de ma\uedz (Zea mays L.) para ensilaje a la aplicaci\uf3n de N en el rendimiento y contenido de prote\uedna del forraje. En el Ensayo 1 los tratamientos correspondieron a dos h\uedbridos de ma\uedz para ensilaje de distinta precocidad, SX-43 e INIA-150, sembrados con una poblaci\uf3n de 90.000 plantas ha-1 y cuatro dosis de N: 0, 100, 200 y 400 kg N ha-1. En el Ensayo 2, los tratamientos fueron dos dosis de N: 200 y 400 kg N ha-1, y tres formas de aplicaci\uf3n de nitr\uf3geno: a) 1/2 a la siembra + 1/2 a 30 cm de altura de las plantas; b) 1/3 a la siembra + 1/3 a 30 cm de altura de las plantas + 1/3 a 60 cm de altura de plantas; y c) 1/4 a la siembra + 1/4 a 30 cm de altura de las plantas + 1/4 a 60 cm de altura de plantas +1/4 en floraci\uf3n. Adem\ue1s se incluy\uf3 un tratamiento sin aplicaci\uf3n de N. En el Ensayo 1, la aplicaci\uf3n de N aument\uf3 el rendimiento de MS (P < 0,05), sin embargo no hubo respuesta significativa entre 100 y 400 kg de N, debido a limitantes de suelo. La producci\uf3n y el porcentaje de prote\uedna del forraje aument\uf3 significativamente con la aplicaci\uf3n de N. En el Ensayo 2, la producci\uf3n de MS en el ma\uedz aument\uf3 con la aplicaci\uf3n de N (P < 0,05). El porcentaje de prote\uedna del forraje se increment\uf3 con mayores dosis de N y su parcializaci\uf3n. Al aumentar la parcializaci\uf3n del N de 2 a 4 aplicaciones se increment\uf3 el tenor proteico del forraje en 23 y 37 % para las dosis de 200 y 400 kg N ha-1, respectivamente

    YqiC of Salmonella enterica serovar Typhimurium is a membrane fusogenic protein required for mice colonization

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    <p>Abstract</p> <p>Background</p> <p><it>Salmonella enterica </it>serovar Typhimurium is an intracellular bacterial pathogen which can colonize a variety of hosts, including human, causing syndromes that vary from gastroenteritis and diarrhea to systemic disease.</p> <p>Results</p> <p>In this work we present structural information as well as insights into the <it>in vivo </it>function of YqiC, a 99-residue protein of <it>S</it>. Typhimurium, which belongs to the cluster of the orthologous group 2960 (COG2960). We found that YqiC shares biophysical and biochemical properties with <it>Brucella abortus </it>BMFP, the only previously characterized member of this group, such as a high alpha helix content, a coiled-coil domain involved in trimerization and a membrane fusogenic activity <it>in vitro</it>. In addition, we demonstrated that YqiC localizes at cytoplasmic and membrane subcellular fractions, that a <it>S</it>. Typhimurium <it>yqiC </it>deficient strain had a severe attenuation in virulence in the murine model when inoculated both orally and intraperitoneally, and was impaired to replicate at physiological and high temperatures <it>in vitro</it>, although it was still able to invade and replicate inside epithelial and macrophages cell lines.</p> <p>Conclusion</p> <p>This work firstly demonstrates the importance of a COG2960 member for pathogen-host interaction, and suggests a common function conserved among members of this group.</p
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