Decomposition from legume and non-legume crop residues: effects on soil organic carbon fractions under controlled conditions; Descomposición de restos de cultivos de leguminosas y no leguminosas: Efectos sobre las fracciones de carbono orgánico del suelo bajo condiciones controladas; Decomposição de resíduos da cultura de leguminosas e não leguminosas: Efeitos, em condições controladas, nas frações de carbono orgânico do solo de Sa Pereira, Eduardo; Duval, Matias Ezequiel; Galantini, Juan Alberto Cover crop (CC) residues protect the soil from erosion and their permanence on the surface is largely influenced by their biochemical constituents. We performed a study under controlled conditions to investigate the dynamics of legume and non-legume CC residues decomposition and the transformations of the soil labile organic carbon fractions in the surface layer (0-15 cm). Theexperiment was carried out on a Typic Argiudoll (clay loam, 27.4 g kg-1 soil organic matter, 14 mg kg-1 extractable phosphorus and 6.5 pH) placed in undisturbed pots (1570 cm3) in a greenhouse under controlled conditions of temperature (25 ± 1 °C). We evaluated three CC species (oat, Avena sativaL.; vetch, Vicia sativa L.; Persian clover, Trifolium resupinatum L.) and a no-CC control (fallow). Shoot residues were applied on the soil surface at 5.4, 5.4 and 2.7 g dry matter (equivalent to 6, 6 and 3 Mg ha-1 for oat, vetch and clover, respectively) and incubated for 362-days (eight sampling times). The water content in the pots was maintained periodically by weight at 60% of soil water-holding capacity. The soil samples were analyzed for particulate organic carbon (POC), and total and soluble carbohydrates (CHt and CHs, respectively). Oat and vetch residues decomposed faster than clover, with the decomposition rate constant (k) values of 1.3, 1.4 and 1.9 year-1, respectively. At the end ofthe experiment, POC concentration was lower in vetch (1.83 g kg-1) and clover (1.96 g kg-1) than in oat (2.21 g kg-1) and fallow (3.00 g kg-1), indicating a loss of 45-64% from their initial values. Soil CHt was influenced by residue quality, where the periods of greatest residue decay (vetch 21-59 daysand oat 93-130 days) corresponded to higher soil CHt. Hence, this organic carbon fraction is sensitive to residue decomposition and can be indicators of changes in soil organic matter over short periods of time.; Los cultivos de cobertura (CC) protegen al suelo de la erosión y su permanencia en el tiempo está influenciada en gran medida por su composición química. Se realizó un estudio en condiciones controladas para investigar la dinámica de descomposición de residuos de CC y las transformaciones de las fracciones orgánicas lábiles en la capa superficial del suelo (0-15 cm). El experimento se llevó a cabo en un Typic Argiudoll (franco arcilloso, 27,4 g kg-1 de materia orgánica del suelo, 14 mg kg-1 de fósforo extraíble y 6,5 de pH) colocado sin disturbar en macetas (1570 cm3 ) en invernadero bajo condiciones controladas de temperatura (25 ± 1 °C). Se evaluaron tres especies de CC (avena, Avena sativa L.; veza, Vicia sativa L. y trébol, Trifolium resupinatum L.) y un control sin CC (barbecho). En la superficie del suelo, se aplicaron 5,4, 5,4 y 2,7 g de materia seca (equivalentes a 6, 6 y 3 Mg ha-1 de avena, veza y trébol, respectivamente) y se incubaron durante 362 días (ocho fechas de muestreo). El contenido de agua en el suelo de las macetas fue mantenido al 60% de la capacidad de retención de agua. En las muestras de suelo se determinó carbono orgánico particulado (POC), y carbohidratos totales y solubles (CHt y CHs, respectivamente). Los residuos de avena y veza se degradaron más rápidamente que el trébol, con tasas de descomposición (k) de 1,3, 1,4 y 1,9 años-1, respectivamente. Al final del experimento, la concentración de POC fue menor en el suelo con veza (1,83 g kg-1) y trébol (1,96 g kg-1) que con avena (2,21 g kg-1) y barbecho (3,00 g kg-1), lo que indica una pérdida de 45-64% de sus niveles iniciales. Los CHt fueron influenciados por la calidad de los residuos, donde los períodos de mayor descomposición de residuos (veza 21-59 días y avena 93-130 días) coinciden con los mayores contenidos de CHt en el suelo. Por lo tanto, esta fracción de carbono orgánico es sensible a la descomposición de residuos y puede ser indicadores de cambios en la materia orgánica del suelo durante cortos períodos de tiempo.; Os resíduos de cobertura (CC) protegem o solo da erosão e a sua permanência na superfície do solo é largamente influenciada pelos seus constituintes bioquímicos. Realizou-se um estudo, em condições controladas, para investigar a dinâmica da decomposição dos resíduos CC provenientes de leguminosas e não leguminosas e as transformações das frações de carbono lábeis na camada superficial do solo (0-15 cm). O ensaio foi realizado em estufa, em condições controladas de temperatura (25 ± 1 °C), num Typic Argiudoll (franco argiloso, com 27,4 g kg-1 de matéria orgânica, 14 mg kg-1 de fósforo extraível e pH 6,5) que foi colocado, sem o perturbar, em vasos (1570 cm3 ). Avaliaram-se três espécies de CC (aveia, Avena sativa L.; ervilhaca, Vicia sativa L. e trevo-da-Pérsia, Trifolium resupinatum L.) e um controlo sem CC (pousio). Na superfície do solo aplicaram-se 5,4; 5,4 e 2,7 g de matéria seca (equivalente a 6; 6 e Mg ha-1 de aveia, ervilhaca e trevo-da-Pérsia, respetivamente) e incubaram-se durante 362 dias (oito datas de amostragem). Nos vasos, o conteúdo em água no solo foi mantido a 60% da sua capacidade de retenção de água. Nas amostras de solo foram analisados o carbono orgânico particulado (POC) e os hidratos de carbono totais e solúveis (CHt e CHs, respetivamente). Os resíduos de aveia e ervilhaca decompõem-se mais rapidamente do que os de trevoda-Pérsia, com valores de taxa de decomposição constante (k) de 1,3; 1,4 e 1,9 ano-1, respetivamente. No final do ensaio, a concentração de POC era mais baixa nos solos com ervilhaca (1,83 g kg-1) e trevo-da-Pérsia (1,96 g kg-1) do que nos solos com aveia (2,21 g kg-1) e em pousio (3,00 g kg-1), indicando uma perda de 45-64% em relação aos valores iniciais. Os valores de CHt no solo foram influenciados pela qualidade dos resíduos, onde os períodos de maior decomposição destes (ervilhaca: 21-59 dias e aveia: 93-130 dias) correspondem às maiores concentrações de CHt no solo. Assim, esta fração de carbono orgânico é sensível à decomposição do resíduo e pode ser um indicador das alterações na matéria orgânica do solo durante curtos períodos de tempo.

Estudio de fluido magnetoreológico con nanopartículas de Níquel y base aceite Mesquida, César Darío; Ramos, Susana Beatriz; Zysler, Roberto Daniel; Soldati, Analía Leticia; Soria, Carlos; Pettinari, Gisela Roxana Los fluidos magnetoreológicos (FMR) son de interés ya que pueden modificar el diseño y el funcionamiento de dispositivos electromecánicos debido a su capacidad de cambiar significativamente su viscosidad bajo la influencia de un campo magnético. Este hecho ha estimulado una intensa actividad de investigación con el objetivo de desarrollar distintas aplicaciones. En este trabajo se sintetizaron y caracterizaron nanopartículas de Ni para su uso como fase dispersaen un FMR utilizando aceite vegetal como fase continua. Para esta suspensión se midió la viscosidad en función del campo magnético y la velocidad de corte, así como el comportamiento viscoelástico en función de una deformación oscilatoria. Se observa que la viscosidad aparente aumenta con el campo magnético aplicado. Además, el campo magnético aplicado induce cambios en las propiedades viscoelásticas del fluido, que pasa a estar dominado por el módulo elástico o de almacenamiento a lo largo de toda la gama de frecuencias ensayadas. El rendimiento viscoelástico de la suspensión de nanopartículas de Ni ensayada revela un interesante comportamiento magnetoreológico, cuando se compara con otros fluidos magnéticos descritos en la literatura, a saber, los desarrollados con partículas comerciales de hierro y óxido de hierro, materiales que generalmente se emplean para este tipo de aplicaciones.; Magnetorheological fluids (MRF) are of interest since they can modify the design and operation of electromechanical devices due to their capacity to significantly change their viscosity under the influence of a magnetic field. This fact has stimulated an intense research activity with the aim of developing applications in electromechanical systems. In this work we synthesized and characterized Ni nanoparticles (Ni NP) for their latter use as a MRF component using vegetal oil as the continuum phase. For this suspension, the shear frequency and magnetic field-dependent viscosity, as well as the viscoelastic behavior as a function of the oscillatory applied load, are measured. It is found that the apparent viscosity increases with the applied magnetic field. Also, the applied magnetic field induces changes in the viscoelastic properties of the fluid, which turns to be dominated by the elastic or storage mode along the whole range of frequencies tested. The viscoelastic performance of the present Ni NP suspension reveals an interesting magnetorheological behavior, when compared to other magnetic fluids reported in the literature, namely, those based on commercial iron and iron oxide particles, materials that are more generally used for this type of applications.

Multiple approaches to understanding the taxonomic status of an enigmatic new scorpion species of the genus Tityus (Buthidae) from the biogeographic island of Paraje Tres Cerros (Argentina) Ojanguren Affilastro, Andres Alejandro; Adilardi, Renzo Sebastián; Cajade, Rodrigo; Ramirez, Martin Javier; Ceccarelli, Fadia Sara; Mola, Liliana Maria Tityus curupi n. sp., belonging to the bolivianus complex, is described from the biogeographically distinct area of Paraje Tres Cerros in north-eastern Argentina. We also present a molecular species delimitation analysis between Tityus curupi n. sp. and its sister species Tityus uruguayensis Borelli 1901 to confirm species integrity. Furthermore, a cytogenetic analysis is presented for these two species which contain different multivalent associations in meiosis, as a consequence of chromosome rearrangements, and the highest chromosome numbers in the genus.

Representantes y representaciones de Argentina en la Organización Internacional del Trabajo en la década de 1920; Argentine's representatives and representations in the International Labor Organization on the 1920´s Stagnaro, Andrés; Caruso, Laura Gabriela El artículo aborda la relación de la Argentina y la Organización Internacional del Trabajo (OIT) a través de los distintos representantes que concurrieron a las Conferencias anuales del organismo durante la década del veinte del siglo pasado, en momentos en que la OIT estaba en proceso formativo. Los informes que estos delegados hicieron públicos -en el caso de los delegados gubernamentales informes elevados a las autoridades, en el caso de los delegados obreros y patronales publicados en diversos medios- permiten analizar las expectativas que portaban al interactuar en un organismo internacional que tenía sus propios objetivos. En muchos casos la OIT fue un escenario más en la disputa entre el estado, los patrones y los obreros, y en otros se puede percibir la uniformidad de criterios en relación a algunos tópicos particulares, tales como el lugar de la Argentina en relación a su legislación laboral. Al mismo tiempo la participación de las delegaciones argentinas exigieron la adecuación del sistema de relaciones establecido entre los sindicatos y el Estado ya que ante la ausencia de un mecanismo formal en la elección de los representantes obreros este fue reemplazado por mecanismos adhoc en el que primaba la coyuntura de conflictividad local; The article approach the relations between the Argentine and the International Labor Organization (ILO) through the different argentine ´s representatives on the ILO´s annual conferences during the formative process on the 1920´s. The representative´s reports –in the case of the government´s representatives those reports were raised to the authorities, in the case of the workers and employers delegates the reports were published in different publications– allowed us to analyze those delegates expectations while they interact with a an organizations with their own objectives. In many cases the ILO was just another stage in the dispute between the state, the workers and the employers, in others we will be able to see the uniformity of criteria in some topics, such as the spot of argentine´s labor legislation. At the same time, Argentine´s participation on the ILO´s conferences demands the adequacy of the relations system between the State and the workers unions. In the absence of this kind of mechanism the workers representative elections depends on the moment of local labor unrest.

Análisis envolvente de datos: Un caso de estudio para una universidad argentina; Data envelopment analysis: A case study for one Argentinian university; Análise envoltória de dados: Um estudo de caso para uma universidade Argentina Villarreal, Fernanda Soledad; Tohmé, Fernando Abel Este artículo presenta un caso de estudio en el que se analiza la eficiencia relativa del plan de estudios de un programa universitario. Esta cuestión es muy relevante, ya que los cursos del plan están financiados con fondos públicos y por lo tanto afectan la eficiencia del gasto público global. El método aplicado es el análisis envolvente de datos (DEA, por sus iniciales en inglés). Los resultados permiten identificar los cursos optativos ineficientes que deberían aumentar el número de estudiantes y reducir al mismo tiempo el número de miembros del cuerpo docente asignados a ellos para mejorar su eficiencia. En el caso de cursos obligatorios, la mejora también requiere reducir el número de docentes auxiliares.; This article presents a study case in which we analyze the relative efficiency of the curriculum of a university degree program. This is a relevant question, since the required courses are publicly funded and thus affect the efficiency of global public spending. The method applied is Data Envelopment Analysis (DEA). Through the our results, we were able to identify inefficient non-mandatory courses that should increase the number of students while reducing the number of faculty members assigned to them to improve their efficiency. In the case of mandatory courses, improvement also requires to reduce the number of adjunct faculty.; Este artigo apresenta um estudo de caso em que a eficiência relativa do currículo de um programa universitário é analisada. Esta questão é muito relevante porque os cursos do plano são de financiamento público e, portanto, afetam a eficiência da despesa pública global. O método aplicado é a análise envoltória de dados (DEA, por sua sigla em Inglês). Os resultados permitem identificar eletivas ineficientes que deveriam aumentar o número de alunos e, ao mesmo tempo, reduzir o número de membros do corpo docente que lhes foram atribuídos para melhorar a sua eficiência. No caso de cursos obrigatórios, a melhoria também requer reduzir o número de assistentes de ensino.

Porphyromona gingivalis, patogeno de relevancia en la enfermedad periodontal Britos, María R.; Sin, Cynthya Solange; Ortega, Silvia Mercedes Porphyromonas gingivalis (P.Gingivalis) es un microorganismo comprometido en el inicio y progresión de la enfermedad periodontal crónica y agresiva, y es considerado su principal agente etiológico. Esta bacteria cuenta con una serie de factores de virulencia que le permiten iniciar el proceso infeccioso, perpetuar la infección y también transformar la placa dental benigna en una comunidad microbiana patógena. Estudiar sus factores de virulencia y su capacidad de modular la respuesta inmunológica del huésped es muy importante para comprender el papel de este patógeno en el desarrollo y establecimiento de la enfermedad. Esta revisión proporciona una visión actual sobre los factores de virulencia y su impacto sobre la respuesta inmunológica en relación con la patogénesis de la enfermedad periodontal.; Porphyromonas gingivalis (P. Gingivalis) is a microorganism involved in the onset and progression of chronic and aggressive periodontal disease, and is considered its main etiological agent. This bacterium has a number of virulence factors that allow it to initiate the infectious process, perpetuate the infection and also transform the benign dental plaque into a pathogenic microbial community. Studying their virulence factors and their ability to modulate the host's immune response is very important in understanding the role of this pathogen in the development and establishment of the disease. This review provides a current view on virulence factors and the irimpac to the immune response in relation to the pathogenesis of periodontal disease.

Artropodofauna cadavérica asociada a cerdo doméstico (sus scrofa) en un ambiente ribereño en Chubut, Argentina; Fauna carrion associated to domestic pig (Sus scrofa) in a coastal environment in Chubut, Argentina Armani, Ana Paula; Dahinten, Silvia Lucrecia V.; Centeno, Néstor Daniel Este es el primer estudio de descomposición cadavérica realizado en un ambiente ribereño en la región NO de la provincia de Chubut Argentina, cuyo objetivo fue determinar la composición específica, la abundancia y la diversidad de la artropodofauna cadavérica asociada a un modelo experimental porcino. Se realizaron muestreos estacionales durante tres años consecutivos (2010 - 2012) utilizando en cada muestreo tres cerdos, colocados dentro de jaulas de madera cubiertas de alambre tejido. Diariamente se colectaron los insectos en el cuerpo, debajo y alrededor de este. Se identificaron y caracterizaron las cinco etapas del proceso de descomposición de los cadáveres de cerdo experimentales. Se recolectaron 6.325 individuos adultos e inmaduros pertenecientes a 63 especies de 18 familias distribuidas entre los órdenes Diptera, Coleoptera e Hymenoptera. Se determinó la estacionalidad de Compsomyiops fulvicrura (Diptera: Calliphoridae) durante la época cálida y la dominancia de Calliphora vicina (Diptera: Calliphoridae) en la época fría. Los resultados obtenidos aportan información relevante sobre la fauna de insectos saprófagos en el ambiente ribereño al río Chubut, que puede ser utilizada como herramienta en la estimación de la data de muerte en casos forenses humanos en la región estudiada.; This is the first study of cadaveric decomposition taking place in a riverside environment of the NW of Chubut province, Argentina. The specific composition, abundance, diversity of the carrion fauna associated with a porcine experimental model was determined. Seasonal samplings were performed for three consecutive years (2010- 2012) using three domestic pigs for each sample, placed in wooden cages covered with wire mesh. Daily, insects were collected in the body, under and around it. There were identified and characterized the five stages of bodies’ decomposition of experimental pigs. Were collected 6,325 individuals adult and immature of 63 species belonging to 18 families distributed among the Diptera, Coleoptera and Hymenoptera orders. During the warm season, was determined the seasonality of Compsomyiops fulvicrura (Diptera: Calliphoridae) and, the dominance of Calliphora vicina (Diptera: Calliphoridae) in the cold season. Relevant information on the saprophagous insects in the riverside environment Chubut, which is helpful in estimating the time of death in forensic cases in the study region.

Revisitando dos estudio clave sobre niños y jóvenes sin domicilio: a propósito de los trabajos de Tobías Hetch y Maryse Marpsat; Rethinking Two Key Studies On Homeless Children and Youth: Regarding the Works of Tobías Hetch and Maryse Marpsat; Revisando dois estudos-chave sobre crianças e jovens sem-teto: sobre o trabalho de Tobias Hetch e Maryse Marpsat Rausky Ndrico, Maria Eugenia Este artículo recupera los aportes de dos trabajos considerados clave en el campo de estudios de niños y jóvenes sin hogar: uno llevado a cabo en Francia por M. Marpsat, J. M. Firdion y equipo "The INED research on homeless", otro, desarrollado en Brasil por T. Hetch "At home in the street", haciéndolos dialogar con una experiencia de investigación conducida en el contexto de la ciudad de La Plata -capital de la provincia de Buenos Aires- sobre niños y jóvenes que trabajan y/o viven en la calle. Se busca hacer una contribución teórica y metodológica a este campo de estudios, a partir del ordenamiento de ciertos ejes de lectura que permitan dilucidar aspectos sustantivos a considerar en investigaciones sobre este colectivo.; This paper focuses on two key research from the area of the social studies on homeless child and youth people: one of them conducted in France by M. Marpsat, J. M. Firdion and their team, “The INED research on homeless”, the other, developed in Brazil by T. Hetch, “At home in the street”. We try to put them in dialogue with a research experience conducted in La Plata —capital of Buenos Aires— about children and youth people who works and/or lives in the streets. This presentation seeks to make a theoretical and methodological contribution to this area of study, sorting out some axis that allows to explain substantive issues to be considered in empirical research on this group.; Neste artigo recupera-se os aportes de duas pesquisas consideradas chave no campo de estudos das crianças e jovens que moran nas ruas: un deles feito na Francia pelo equipe da M. Marpsat y do J.M Firdion “The INED research on homeless”, e outro, desenvolvido no Brasil pelo T. Hetch “At home en the Street”, eles são postos em diálogo com una pesquisa feita na cidade de La Plata –capital do Estado de Buenos Aires- sobre crianças e jovens que trabalhan ou moran nas ruas. Procura-se fazer uma contribuição teórico-metodológica neste campo de estudos, fazendo um ordenamento de alguns eixos de letura que ajudem a elucidar questões substantivas a serem considerados na pesquisa sobre esses grupos.

A high precision U–Pb radioisotopic age for the Agrio Formation, Neuquén Basin, Argentina: Implications for the chronology of the Hauterivian Stage Aguirre-Urreta, Maria Beatriz; Schmitz, Mark; Lescano, Marina Aurora; Tunik, Maisa Andrea; Rawson, Peter F.; Concheyro, Graciela; Buhler, Mariano; Ramos, Victor Alberto A new CA-ID TIMS U–Pb age of 130.39 ± 0.16 Ma is presented here from the Pilmatué Member of the Agrio Formation, lower Hauterivian of the Neuquén Basin in west-central Argentina. This high precision radioisotopic new age, together with the two former ones from the upper Hauterivian Agua de la Mula Member of the Agrio Formation and modern cyclostratigraphic studies in the classical sections of the Mediterranean Province of the Tethys indicate that the Hauterivian Stage spans some 6 Ma, starting ca. 132 Ma and ending ca. 126 Ma. These radioisotopic ages are tied to ammonite biostratigraphy and calcareous nannofossil bioevents and biozones recognized in the Neuquén Basin which in turn are correlated with the Mediterranean standard zones. A new geological time scale for the Valanginian–Hauterivian stages in the Mediterranean region integrating astrochronological and radiochronological data differs with the current official geological time scale which still maintains poorly constraint absolute ages for the Berriasian-Aptian interval.

Functional morphology of comminuting feeding structures of Trichodactylus borellianus (Brachyura, Decapoda, Trichodactylidae), an omnivorous freshwater crab de Azevedo Carvalho, Débora; Viozzi, María Florencia; Collins, Pablo Agustin; Williner, Verónica Crustaceans exhibit great diversity of feeding structures with morphological traits that are useful to infer the general trophic habits of species. In this study, we analyzed the functional morphology of comminuting feeding structures (mandibles, chelipeds, gastric mill) of the freshwater crab Trichodactylus borellianus directly related with the food fragmentation. The heterochely and mechanical advantage (MA) of the chelae were also studied. In both analyses, we considered the relationship between morphology and the natural diet. We expected to find a consistent relation between feeding habits and morphological traits. In general, we found simple structures armed with uniform setal systems and feeding appendages without pronounced teeth or spines. Mandibles have primarily cutting functions, helping with the food anchoring and fragmentation with mandibular palps armed with pappose setae. Chelipeds were covered with spines and simple setae. Adult males exhibited right-handedness with high MA of the major chelae. The ingested, relatively large pieces of food are finally chewed by a gastric mill equipped with sharp cusps characteristic of decapods with low ingestion of crude fiber material. The morphology of the feeding apparatus revealed that it is well adapted to an omnivorous diet, being able to cope with dietary changes.

Pericardial fat volume is related to atherosclerotic plaque burden rather than to lesion severity Rodriguez Granillo, Gaston Alfredo; Carrascosa, Patricia; Deviggiano, Alejandro; Capunay, Carlos; De Zan, Macarena C.; Goldsmit, Alejandro; Campisi, Roxana Aims: We sought to explore the relationship between pericardial fat volume (PFV) and both coronary atherosclerosis (CA) extent and severity using coronary artery calcium score (CAC), computed tomography coronary angiography (CTCA), and invasive coronary angiography in patients at high to intermediate likelihood of coronary artery disease (CAD). Methods and results: Patients clinically referred to invasive angiography who underwent CTCA and CAC within 1 month before the procedure comprised the study population. PFV, CAC, atherosclerotic burden indexes [segment involvement score (SIS); segment stenosis score; three-vessel plaque; and any left main plaque], and the invasive angiography-derived CAD index were evaluated independently. A total of 75 patients were included in the study. PFV did not differ between patients with or without obstructive (stenosis .70%) CAD defined by invasive angiography (86.4±31.7 vs. 77.1±42.8 cm3, P = 0.34), although patients with obstructive CAD had significantly higher CAC scores [636.0 (IQR 229.5-1101.0) vs. 206.0 (IQR 0.0-675), P<0.0001] than patients without obstructive CAD. Patients with extensive CA (SIS . 5) had significantly larger PFV (89.9±33.9 vs. 58.7±33.2 cm3, P = 0.003) than patients with non-extensive CA. Significant correlations were found between PFV and CAC (r = 0.49, P<0.0001), and SIS (r = 0.46, P<0.0001), whereas very weak correlations were observed between PFV and the CAD index (r = 0.27, P = 0.02), and between PFV and the body mass index (r = 0.33, P = 0.004). Conclusion: The main finding of the present study was the identification of PFV as more closely related to atherosclerotic plaque burden rather than to lesion severity in patients referred to invasive coronary angiography.

Relationship between ivermectin concentrations at the injection site, muscle and fat of steers treated with traditional and long-acting preparations Iezzi, Sebastián Juan; Purslow, Peter; Christensen, Sara; Lanusse, Carlos Edmundo; Lifschitz, Adrian Luis Ivermectin (IVM) is broad-spectrum compound active against endo and ecto-parasites of clinical relevance in veterinary and human medicine. It is commercially available to use in livestock animals as injectable formulations containing 1% IVM and also as a concentrated (3.15%) long-acting (LA) preparation. The potential risk of the presence of high concentrations of drug residues in muscle tissue at the injection site is therefore a concern. The aim of this study was to determine the relationship between the IVM residual concentrations at the injection site, in comparison to the untreated contralateral neck (control muscle) and in fat from cattle treated with different preparations. Healthy steers received one of the following subcutaneous treatments in the neck area: Group A: IVM-LA 3.15% preparation and Group B: IVM 1%. After a withdrawal period for each formulation the animals were sent to the slaughterhouse. IVM concentrations at the injection site were detected among animals treated with the LA formulation, with high residual concentrations of IVM (between 15 and 141 μg/kg) in the injection site of two steers. However, the residual concentrations of IVM at the injection site obtained after the subcutaneous administration of the LA preparation do not represent a toxicological risk to consumers.

Riesgo neurológico en el niño de mediano riesgo neonatal Vericat, Agustina; Orden, Alicia Bibiana INTRODUCCIÓN: los neonatos de mediano riesgo suelen presentar alteraciones del neurodesarrollo, sutiles o inaparentes, que pueden evidenciarse a mediano y a largo plazos; es por ello que se les considera niños de riesgo neurológico. La identificación de los factores de riesgo asociados con los problemas del neurodesarrollo es un primer paso para prevenir o reducir sus efectos. OBJETIVO: con esta revisión cualitativa de la literatura especializada pretendemos describir las características de un grupo de neonatos denominados colectivamente recién nacidos de mediano riesgo neonatal y que, al nacer, no presentan compromiso evidente del desarrollo neurológico. Indagamos, también sobre los factores etiológicos asociados con esta condición. MATERIALES Y MÉTODOS: realizamos una búsqueda bibliográfica en las bases Scientific Electronic Library Online (SciELO), Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS), la Biblioteca Nacional de Medicina de Estados Unidos de Norte América (NLM-Medline) y la Red de Revistas Científicas de América Latina y el Caribe, España y Portugal (RedALyC) centrada en factores de riesgo neurológico. RESULTADOS: el incremento de los controles prenatales, la reducción de los nacimientos pretérmino y del parto por cesárea son factores relevantes para el óptimo neurodesarrollo. Luego del parto es necesario extremar los cuidados del neonato en las Unidades de Cuidado Intensivo Neonatal controlando cuadros tales como la hiperbilirrubinemia, la sepsis neonatal y la dificultad respiratoria, asociados con alteraciones del desarrollo en los neonatos de mediano riesgo. CONCLUSIONES: las intervenciones para evitar o reducir el riesgo neurológico en los neonatos de mediano riesgo deben establecerse desde el inicio de la gestación y continuar durante toda la permanencia en las Unidades de Cuidado Intensivo Neonatal.

The jamming constant of uniform random graphs Bermolen, Paola; Jonckheere, Matthieu Thimothy Samson; Moyal, Pascal By constructing jointly a random graph and an associated exploration process, we define the dynamics of a “parking process” on a class of uniform random graphs as a measure-valued Markov process, representing the empirical degree distribution of non-explored nodes. We then establish a functional law of large numbers for this process as the number of vertices grows to infinity, allowing us to assess the jamming constant of the considered random graphs, i.e. the size of the maximal independent set discovered by the exploration algorithm. This technique, which can be applied to any uniform random graph with a given–possibly unbounded–degree distribution, can be seen as a generalization in the space of measures, of the differential equation method introduced by Wormald.

Algoritmos de punto de cambio aplicados a la detección de estructuras vorticosas en flujos turbulentos; Change point algorithms applied to the detection of vortex structures in turbulent flows Marañon Di Leo, Julio; Calandra, M. V.; Delnero, Juan Sebastian En este trabajo se presenta el análisis de la aplicación del modelo de un algoritmo de punto de cambio (Change Point Model, CPM), basado en tests no paramétricos, para la detección de estructuras turbulentas en un flujo de aire. Se busca detectar los vórtices generados en la estela de un perfil aerodinámico dotado de un dispositivo de control pasivo de flujo (mini flap de Gurney) ubicado en el borde de fuga. De la muestra de datos obtenida se analiza la aplicación de modelos CPM, con el fin de determinar los posibles cambios de la fluctuación de la velocidad sensada, comparando los resultados con análisis tradicionales. El objetivo principal del estudio es el de detectar las frecuencias características de las estructuras turbulentas inmersas en el campo del flujo. De los resultados obtenidos se desprende que el modelo CPM basado en el test de Cramer-von Mises (CPM-CvM) presenta una buena concordancia con las detecciones esperadas (diferencias menores al 9,5%), mostrando ser una herramienta alternativa para el análisis de estos tipos de flujo en tiempo real. Este trabajo muestra, finalmente, una nueva aplicación para CPM en la detección de cambios en señales aleatorias dependientes del tiempo que tienen una distribución, a priori, desconocida.; The present work shows the application of a change point model (CPM) algorithm, based on non-parametric tests, to turbulent structures detection in an airflow. It seeks to detect the vortices generated in the wake of an airfoil, equipped with a passive flow control device (Gurney mini flap) in its trailing edge. By applying CPM models to the sample data, this paper seeks to determine the possible changes to the velocity fluctuations and compare the model's effectiveness to traditional methods. The main objective of this study is to detect the characteristic frequencies of the turbulent structures immersed in the airflow. The results show that the CPM methodology, based on the Cramer- von Mises (CPM-CvM) test, produces results that coincide with values predicted by traditional methods (less than 9.5% of mismatch), validating its use as a real time alternative tool for the analysis of these types of flows. Finally, this work shows a new application of CPM for detecting changes in a time-dependent random signal, which has an a priori unknown distribution.

Inoculation with Azospirillum sp. and Herbaspirillum sp. Bacteria Increases the Tolerance of Maize to Drought Stress Curá, José Alfredo; Franz, Diego Reinaldo; Filosofía, Julián Ezequiel; Balestrasse, Karina Beatriz; Burgueño, Lautaro Exequiel Stress drought is an important abiotic factor that leads to immense losses in crop yields around the world. Strategies are urgently needed to help plants adapt to drought in order to mitigate crop losses. Here we investigated the bioprotective effects of inoculating corn grown under drought conditions with two types of plant growth-promoting rhizobacteria (PGPR), A. brasilense, strain SP-7, and H. seropedicae, strain Z-152. Plants inoculated with the bacteria were grown in a greenhouse with perlite as a substrate. Two hydric conditions were tested: normal well-watered conditions and drought conditions. Compared to control non-inoculated plants, those that were inoculated with PGPR bacteria showed a higher tolerance to the negative effects of water stress in drought conditions, with higher biomass production; higher carbon, nitrogen, and chlorophyll levels; and lower levels of abscisic acid and ethylene, which are plant hormones that affect the stress response. The oxidative stress levels of these plants were similar to those of non-inoculated plants grown in well-watered conditions, showing fewer injuries to the cell membrane. We also noted higher relative water content in the vegetal tissue and better osmoregulation in drought conditions in inoculated plants, as reflected by significantly lower proline content. Finally, we observed lower gene expression of ZmVP14 in the inoculated plants; notably, ZmVP14 is involved in the biosynthesis of abscisic acid. Taken together, these results demonstrate that these bacteria could be used to help plants cope with the negative effects of drought stress conditions.

Hybrid process for the purification of water contaminated with nitrites: Ion exchange plus catalytic reduction Mendow, Gustavo; Grosso, César L.; Sánchez, Agustina; Querini, Carlos Alberto Water polluted with nitrites represents a big risk to human health. In this work, palladium supported on macroporous anionic exchange resin was used in the catalytic nitrite reduction. This process is compared with the traditional ion exchange procedure using the same catalytic resin. Both, the resin and the catalyst behaviour were evaluated in a fix-bed reactor, feeding water containing nitrites and other competitor ions, such as sulphate, bicarbonate, and chlorides, and adjusting the pH with carbon dioxide. When feeding water containing only nitrites, it was observed that the catalytic reduction makes it possible to treat 55% more water than when using the ion exchange process, at the same level of nitrites elimination. Moreover, in steady state it was possible to obtain a nitrite conversion to nitrogen of 54% with high selectivity, obtaining an ammonium concentration lower than 0.2 mg/L. In the case of having other ions present in the system, both the conversion and the selectivity decreased. A regeneration strategy is also developed, using a very low hydrogen flow rate at atmospheric pressure and room temperature. This treatment leads to the reduction of more than 99% of the nitrites present in the contaminated water. The catalyst was used in several consecutive cycles maintaining a very good performance, even in the presence of competitor ions. The process was scaled up to a pilot level obtaining identical results.

Wnt/β-catenin pathway in the prefrontal cortex is required for cocaine-induced neuroadaptations Cuesta, Santiago; Severin, María Julia; Batuecas, Jorgelina; Rosso, Silvana Beatriz; Pacchioni, Alejandra Maria Behavioral sensitization is a progressive and enduring enhancement of the motor stimulant effects elicited by repeated administration of drugs of abuse. It can be divided into two distinct temporal and anatomical domains, termed initiation and expression, which are characterized by specific molecular and neurochemical changes. This study examines the role of the Wnt canonical pathway mediating the induction of cocaine sensitization. We found that β-catenin levels in the prefrontal cortex (PFC), amygdala (Amyg) and dorsal striatum (CPu) are decreased in animals that show sensitization. Accordingly, GSK3β activity levels are increased in the same areas. Moreover, β-catenin levels in nuclear fraction, mRNA expression of Axin2 and Wnt7b are decreased in the PFC of sensitized animals. Then, in order to demonstrate that changes in the PFC are crucial for initiation of sensitization, we either rescue β-catenin levels with a systemic treatment of a GSK3β inhibitor (Lithium Chloride) or inhibit Wnt/β-catenin pathway with an intracerebral infusion of Sulindac before each cocaine injection. As expected, rescuing β-catenin levels in the PFC as well as CPu and Amyg blocks cocaine-induced sensitization, while decreasing β-catenin levels exclusively in the PFC exacerbates it. Therefore, our results demonstrate a new role for the Wnt/β-catenin pathway as a required neuroadaptation in inducing behavioral sensitization.

Higgsino-like dark matter from sneutrino late decays Medina, Anibal Damian We consider Higgsino-like dark matter (DM) in the Minimal Supersymmetric Standard Model (MSSM) with additional right-handed neutrino chiral superfields, and propose a new non-thermal way of generating the right amount of relic DM via sneutrino late decays. Due to the large DM annihilation cross-section, decays must occur at lower temperatures than the freeze-out temperature Td≪TF,χ˜1 0∼μ/25, implying a mostly right-handed lightest sneutrino with very small Yukawa interactions. In that context, the right amount of Higgsino-like DM relic density can be accounted for if sneutrinos are produced via thermal freeze-in in the early Universe.

La tormentosa relación entre las grasas y el desarrollo de la diabetes mellitus de tipo 2: actualizado: parte 1 Costa Gil, José Esteban; Spinedi, Eduardo Julio En esta parte de la revisión se describe la relación funcional entre el metabolismo de los lípidos y los hidratos de carbono y su interdependencia, desde el ciclo glucosa-ácido grasos y la hipótesis portal de la insulinorresistencia a los nuevos conocimientos sobre los adipocitos marrones y beiges, con énfasis en el normal funcionamiento de un patrón endocrino cuya disfunción es clave en la fisiopatología de la DMT2 y la obesidad. Se discute la ectopia o el asiento de grasa en el tejido magro por incapacidad del tejido adiposo para seguir acopiando lípidos y la actividad endocrina del adipocito, con la producción de moléculas (adipoquinas) que influyen sobre los mecanismos inductores de insulinorresistencia (leptina, adiponectina, TNF-α, resistina, etc.) y disfunción de la célula beta. Se describen la disminución de la capacidad oxidativa en la cadena respiratoria mitocondrial y el renacer del concepto de lipogénesis de novo, ambas favoreciendo el acopie de lípido intracelular. En tejidos magros existen pequeñas reservas intracelulares de lípidos que mantienen la regulación de funciones esenciales, aunque si aparece una sobrecarga lipídica el fenómeno conduciría a una disfunción (lipotoxicidad) y a la muerte celular (lipoapoptosis). La tormentosa relación entre los lípidos y el islote de Langerhans va más allá del esfuerzo funcional que impone la insulinorresistencia periférica sobre la célula β, por efectos directos de los lípidos o de sus derivados sobre la función del islote pancreático. Sin déficit de insulina no se desarrolla diabetes.