95 research outputs found

    Asteroid trace fossils from Lower Cretaceous shallow- to marginal-marine deposits in Patagonia

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    Most stellate trace fossils of the ichnogenus Asteriacites are attributed to asterozoan producers in general and the majority is the result of the work of ophiuroids. The fossil record of asterozoans is scarce in South America, particularly for the Mesozoic. Asteriacites specimens found in shallow- to marginal-marine Lower Cretaceous (upper Hauterivian-lower Barremian) deposits in the Neuquen Basin (Patagonia, Argentina) exhibit sculpture and morphometry typical of asteroid producers. This is the second record of asteroids from the Lower Cretaceous of South America. The close association between these Asteriacites possibly produced by astropectinids and traces assignable to Siphonichnidae are suggestive of a predator-prey interaction, adding palaeoecological information for community-structure reconstruction of these deposits. For ichnotaxonomic evaluation, morphometric parameters of Asteriacites were elaborated using simple photogrammetric procedures applied on negative epirelief specimens and undertraces to define edges of the stellate trace fossils

    Oxfordian microbial laminites from La Manga Formation, Neuquén Basin, Argentina: Remarkable nanobacteria preservation

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    Exceptionally preserved stromatolites have been found in the shallow marine carbonate facies of the Callovian-Oxfordian La Manga Formation, in the Neuquén Basin (Argentina). The stromatolites exhibit planar and crinkle lamination, often disrupted by sheet-cracks, mudcracks, and fenestral structures, which indicate periodic subaerial exposure. These and other evidences suggest that these stromatolites grew in low energy upper intertidal to lower supratidal environments. They consist of fine micrite/microsparite crystal fabrics (with a remarkable lack of allochems) that define submillimiter alternations of dense laminae. Extensive SEM examinations of polished samples of the stromatolites reveal exceptional preservation of rod-shaped bacteria, coccoid like microorganisms, and abundant aggregates of framboidal pyrite. The rod-like bacteria consists of a network of irregular distributed filaments, which range from 150 nm to an uncommon 640 nm in length; diameters range from 54 nm to 90 nm. Subspherical bodies range in size between 70 and 89 nm. The presence of abundant framboidal pyrites is interpreted as the result of the metabolic activity of sulfate–reducing bacteria and decay of organic matter.Se describen estromatolitos excepcionalmente preservados en facies carbonáticas marinas someras en la Formación La Manga, de edad Calloviense-Oxfordiense, en la Cuenca de Neuquén (Argentina). Los estromatolitos muestran una laminación tanto planar como ondulada, frecuentemente alterada por estructuras de tipo fenestral, y sheet y mud-crack, que indican etapas de exposición subaérea. Estas y otras características sugieren que estos estromatolitos crecieron en ambientes de baja energía, intermareales altos y supramareales. Están constituidos por una fábrica de micrita-microesparita (con una destacada ausencia de aloquímicos) que constituyen alternancias submilimétricas de laminación densa. Estudios detallados con SEM sobre muestras pulidas revelan una preservación excepcional con morfología alargada, microorganismos tipo cocoide, y abundantes agregados de pirita framboidal. Las bacterias con morfologías alargadas están constituyendo una red irregularmente distribuida de filamentos que oscilan en tamaño desde 150 nm hasta, excepcionalmente, 640 nm en longitud; el diámetro oscila entre 50 nm y 90 nm. Las morfologías subesféricas oscilan entre 70 nm y 89 nm. La presencia de abundantes piritas framboidales es interpretada como resultado de una actividad metabólica de bacterias sulfato-reductoras y la descomposición de materia orgánica

    Diversidad de ascomicetes termorresistentes de suelo de la provincia de La Rioja, Argentina

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    Los ascomicetes termorresistentes presentan estructuras tales como ascosporas, clamidosporas y esclerocios, entre otras, que conservan su viabilidad después de haber sido sometidas a choques térmicos (calentamiento mayor a 60 ºC durante minutos a horas). En el presente trabajo se analizó la diversidad de ascomicetes termorresistentes en muestras de suelo de la Provincia de La Rioja, como parte de un estudio sobre la micobiota de suelos áridos del Noroeste argentino. Se recolectaron 39 muestras durante agosto del año 2018. Se transfirieron asépticamente 5 gramos de cada muestra a 100 ml de agar con extracto de malta con cloranfenicol fundido a 75 ºC, temperatura que se mantuvo durante 30 minutos. La suspensión se transfirió a cajas de Petri y, una vez solidificado el medio, éstas fueron incubadas a 30 ºC durante un mes. Para identificar los aislados fúngicos se realizó su caracterización fenotípica. Los caracteres morfológicos se documentaron mediante microscopio de campo claro y electrónico de barrido. Se obtuvieron 111 cepas de 26 muestras (en 13 muestras no hubo desarrollo fúngico). Se identificaron 57 cepas de Aspergillus sección Fumigati, 42 de ellas presentaron holomorfo (ex Neosartorya) y 15 solamente anamorfo. A nivel de especie, se reportan Aspergillus fischeri, A. shendaweii y A. tatenoi. Diferentes especies de los géneros Acremonium, Cladosporium, Hamigera, Leiothecium, Penicillium, Rhizopus y Talaromyces pudieron también ser documentadas. En las condiciones de cultivo estudiadas 37 aislamientos no presentaron esporulación. El presente trabajo es el primero sobre el conocimiento de la diversidad de los ascomicetes termorresistentes de suelo de La Rioja.Fil: Romero, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Ambrosino, Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Comerio, Ricardo Mario. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; ArgentinaFil: Rodríguez Andrade, E.. Universitat Rovira I Virgili; EspañaFil: Stchigel, A. M.. Universitat Rovira I Virgili; EspañaXXXVII Jornadas Argentinas de BotánicaSan Miguel de TucumánArgentinaSociedad Argentina de Botánic

    The Risk of Obstetric Complications and the Effects of Treatment in Women with Low Titer and Medium-High Titer Anti-Phospholipid Antibodies

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    Background/Purpose: The association of low titer anti-phospholipid antibodies (aPL) with obstetric anti-phospholipid syndrome (APS) is increasingly acknowledged, even though some studies have showed conflicting results. To raise further evidence on the relevance of low titer aPL in pregnancy morbidity (PM), we retrospectively reviewed the clinical records of pregnant women attending a joint obstetric/rheumatology clinic over the years 2009-2016. Methods: Patients were included when positive in at least one criteria aPL assay, at any titer, in two occasions minimum 12 weeks apart. Statistical analysis was performed using R package. Results: 111 women (338 pregnancies) were identified. 51 women displayed low-titer aPL, with 160 pregnancies. 60 patients carried aPL at medium-high titers, with 178 pregnancies. 4 patients (4%) had thrombotic APS, 27 (24%) obstetric APS, 7 (6%) thrombotic and obstetric APS, 15 (14%) medium-high titer aPL and non criteria PM, 7 (6%) medium-high titer aPL and no PM, 18 (16%) low titer aPL and non criteria PM and 15 (14%) low titer aPL and no PM. Low-titer aPL were significantly associated with pregnancy complications (c2=8.82, p=0.003). Considering 245 untreated pregnancies, a significant difference in PM distribution was noted for low titer and medium-high titer aPL (p=0.003, Table 1). Among patients with low titer aPL, treatment with low molecular weight heparin [LMWH] + low-dose aspirin [LDASA] significantly improved pregnancy outcomes (p<<0.001, odds ratio [OR]=0.07, 95% CI=0.007\u20130.300), leading to a 14.3-fold reduction of obstetric complications. Hydroxychloroquine [HCQ] was not associated with a significant improvement in live birth rate (p=0.079). Among women with medium-high titer aPL, the standard therapeutic approach with LMWH+LDASA resulted in a significant improvement of obstetric outcome (p<<0.001, OR=0.20, 95% CI=0.100\u20130.400). HCQ treatment significantly improved obstetric outcome, carrying a 3-fold increase in the live birth rate (p=0.025, OR=0.34, 95% CI=0.117\u20130.894). Conclusion: According to our data, low titer aPL are significantly associated with aPL-associated obstetric complications, with a lower prevalence of premature birth compared to medium-high titer aPL. Treatment with LDASA+LMWH led to a higher increase of live birth rate in women with low titer aPL compared to those with medium-high titer aPL. Additional treatment such as HCQ were effective in women with medium-high titer aPL but not those with low titer aPL. Table 1. Obstetric outcomes (defined according to Miyakis et al, 2006) in 245 untreated pregnancies in women with low titer and medium-high titer anti-phospholipid antibodies

    Asociación de marcadores genómicos para consumo residual en genes de IGF1 y neuropéptido Y con la conducta ingestiva de terneras Angus en pastoreo

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    En bovinos, el consumo residual (CR), medido a corral, está asociado a la presencia de alelos particulares en diferentes sitios del genoma con polimorfismos de un solo nucleótido (SNP). La asociación de estas variantes génicas con la conducta ingestiva en pastoreo no ha sido estudiada en ganado para carne. El objetivo de este trabajo fue determinar si existe una asociación entre la presencia de marcadores genómicos para CR en SNP de genes de IGF1 y neuropéptido Y (NPY) y la conducta ingestiva de terneras Angus en pastoreo.Fil: Milano, G. D.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Nadin, L. B.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Producción Animal; ArgentinaFil: Bakker, Maria Leontina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Producción Animal; ArgentinaFil: Quintana, Silvina. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Giustina, S.. No especifíca;Fil: Comerio, A.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Herrera, R.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Hoffer, L. W.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Rigueiro, M.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina44° Congreso Argentino de Producción AnimalArgentinaAsociación Argentina de Producción AnimalUniversidad Nacional de Comahu

    A tetracationic porphyrin with dual anti-prion activity

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    Prions are deadly infectious agents made of PrPSc, a misfolded variant of the cellular prion protein (PrPC) which self-propagates by inducing misfolding of native PrPC. PrPSc can adopt different pathogenic conformations (prion strains), which can be resistant to potential drugs, or acquire drug resistance, hampering the development of effective therapies. We identified Zn(II)-BnPyP, a tetracationic porphyrin that binds to distinct domains of native PrPC, eliciting a dual anti-prion effect. Zn(II)-BnPyP binding to a C-terminal pocket destabilizes the native PrPC fold, hindering conversion to PrPSc; Zn(II)-BnPyP binding to the flexible N-terminal tail disrupts N- to C-terminal interactions, triggering PrPC endocytosis and lysosomal degradation, thus reducing the substrate for PrPSc generation. Zn(II)-BnPyP inhibits propagation of different prion strains in&nbsp;vitro,&nbsp;in neuronal cells and organotypic brain cultures. These results identify a PrPC-targeting compound with an unprecedented dual mechanism of action which might be exploited to achieve anti-prion effects without engendering drug resistance

    An interdisciplinary system dynamics model for post-disaster housing recovery

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    Many previous disasters have demonstrated the need for extensive personal, public, and governmental expenditures for housing recovery highlighting the importance of studying housing recovery. Yet, much research is still needed to fully understand the multi-faceted and complex nature of housing recovery. The goal of this paper is to present a holistic model to further the understanding of the dynamic processes and interdependencies of housing recovery. The impetus for this work is that inequalities in housing recovery could be addressed more effectively if we better understood interconnected factors and dynamic processes that slow down recovery for some. Currently, there is a lack of understanding about such factors and processes. Literature from engineering and social sciences was reviewed to develop an integrated system dynamics model for post-disaster housing recovery. While it is beyond current capabilities to quantify such complexities, the presented model takes a major stride toward articulating the complex phenomenon that is housing recovery
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