106 research outputs found

    The Gondwanan heritage of the Eocene–Miocene Patagonian floras

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    The breakup of Gondwana and the associated climatic changes led to the fragmentation of floras that were once connected across the Southern lands. The diversity of the Gondwanan remnants has long been assumed to have fluctuated in Patagonia across the Cenozoic, although it has never been quantified so far. Here we address when the major floristic members of the Gondwanan legacy (e.g., southern beeches, proteas, podocarps, gumtrees) expanded, contracted, or became extinct during the Patagonian biogeographic isolation (Eocene–Miocene) on the basis of the re-assessment of the fossil record (i.e., woods, leaves, and spore-pollen grains). We found that the Patagonian floras experienced moderate to severe shifts in the diversity of the Gondwanan component —relative to the total flora— with the highest estimates in the late Eocene–early Oligocene (~50%) and the lowest estimates in the late Miocene (~20%) according to the fossil pollen record. The most important floristic changes include two major replacements: 1) tropical Gondwanan taxa (e.g., Akania, Eucalyptus, Gymnostoma) by typically cool-temperate taxa (e.g., Nothofagaceae) in the Eocene, and 2) humid taxa (e.g., Podocarpaceae) by arid-adapted floras, mostly of non-Gondwanan affinity, across the Miocene. The variation in diversity of the Gondwanan component from Patagonia shows a striking resemblance to that from Australia for the same period, probably indicating a global-scale driver of floristic turnover (e.g., global cooling conditions). Today, the Patagonian subantarctic forests harbor only about ~15% of the Gondwanan diversity, representing a three-fold decrease from its climax in the late Eocene–early Oligocene.Fil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Palazzesi, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pujana, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Panti, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Tapia, Mariano Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Fernández, Damián Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Noetinger, Maria Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

    Floras del Mioceno de Patagonia austral, evidencias palinológicas en el noroeste de Santa Cruz

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    La historia evolutiva de las plantas durante el Cenozoico ha sido objeto de diversas contribuciones paleontológicas que enriquecieron el conocimiento científico acerca de las floras y los climas que afectaron y modificaron el paisaje patagónico en el pasado geológico reciente. La paleopalinología en particular se destaca como disciplina para las reconstrucciones paleoambientales mediante el estudio de la materia orgánica fósil y, en especial, los palinomorfos. Esta contribución intenta reconstruirla paleoflora y paleoambientes miocenos en la región del Lago Posadas/Meseta Belgrano, al noroeste de la provincia de Santa Cruz, mediante el análisis palinológico. Con este fin, se analizaron en microscopía óptica 10 muestras fértiles provenientes de la Formación El Chacay. Las asociaciones recuperadas muestran un predominio de las formas continentales (esporas, polen y algas de agua dulce) sobre las marinas (acritarcas, dinoquistes y prasinofitas). Entre las formas continentales dominan los granos de polen asignables a elementos de bosque como las notofagáceas (Nothofagidites spp.), araucariáceas (Araucariacites australis) y podocarpáceas (Podocarpidites spp.), elementos de vegetación abierta como las amarantáceas, anacardiáceas,poáceas, restionáceas y efedráceas (Chenopodipollis chenopodiaceoides, Striatricolporites gamerroi, Graminiidites sp., Milfordia argentina y Equisetosporites claricristatus) y esporas de helechos de cyatheáceas,dicksoniáceas y polypodiáceas(Cyathidites spp., Cyatheacidites annulatus y Laevigatosporites ovatus), que habrían conformado el sotobosque. Las variaciones cuantitativas de estos palinomorfos sugieren una microflora integrada por bosques, vegetación abierta y plancton asociada con la depositación de un ambiente marino costero a estuárico. La presencia de formas polínicas como Mutisiapollis viteauensis, Baumanipollis variaperturatus y Rhoipites cienaguensis permiten ubicar esta microflora en el entorno del Mioceno temprano.Fil: Tapia, Mariano Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Palazzesi, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Ottone, Eduardo Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Cuitiño, José Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaXXXVII Jornadas Argentinas de BotánicaTucumánArgentinaSociedad Argentina de Botánic

    Differentiation of bee pollen samples according to their intact-glucosinolate content using canonical discriminant analysis

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    Producción CientíficaA study is presented of the real possibilities of glucosinolate content and chemometrics (canonical discriminant analysis) to differentiate bee pollen samples from four different apiaries (Fuentelahiguera, Monte, Pistacho, Tío Natalio) located in the same geographical area. Fifteen intact-glucosinolates were quantified by means of ultraperformance liquid chromatography coupled to a quadrupole time-of-flight mass detector in forty-nine bee pollen samples. Glucosinolate residues were detected in most of the samples, and these differed in number and concentration. It was possible to directly differentiate one of the apiaries (Fuentelahiguera) from the other three (Monte, Pistacho y Tío Natalio) by comparing glucosinolate content. These three apiaries were differentiated by means of the first two canonical variables obtained from a canonical discriminant analysis. Following this analysis, more than 88% of the samples could be assigned correctly to the Pistacho and Monte apiaries, and 100% to the Tío Natalio apiary.Este trabajo forma parte de los proyectos de investigación financiados por el Ministerio de Economía y Competitividad e INIA-FEDER (RTA2015-00013-C03-01 y 03)

    Differentiation of bee pollen samples according to the apiary of origin and harvesting period based on their amino acid content

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    Producción CientíficaBee pollen is currently one of the most widely consumed dietary supplements due to its high nutritional value and its potentially beneficial effects on health. Unfortunately, in recent years an increase in the fraudulent marketing of this product has been detected, mainly in terms of adulteration with pollen from other sources. This has made it necessary to seek new tools to ensure its authentication. Therefore, this study investigates the use of free amino acids as markers of the geographical origin and harvesting period of bee pollen. To demonstrate their potential as biomarkers, 72 samples from four apiaries (Pistacho, Tío Natalio, Monte and Fuentelahiguera), located in the same geographical area (Marchamalo, Guadalajara, Spain), were analyzed by liquid chromatography-fluorescence detection, with the data obtained undergoing canonical discriminant analysis. Variable amounts and numbers of free amino acids were found in the samples analyzed; proline predominated in all of them, in a concentration range of 298–569989 mg/kg. The differences observed in amino acid composition could be attributed to the flowering plants from which the bee pollen samples originated. In addition, it was possible to statistically assign over 75% of the samples to the corresponding apiary of origin, the best results being obtained for the Fuentelahiguera and Tío Natalio apiaries (100%); this classification was even superior in the case of the harvesting periods, as more than 90% of the samples were correctly assigned, and in one period (June) a 100% rate was obtained.Ministerio de Economía, Industria y Competitividad (projects RTA 2015-00013-C03-01 and RTA 2015-00013-C03-03

    Mineral composition of bee pollen and its relationship with botanical origin and harvesting period

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    Producción CientíficaIn the present study, the mineral composition of seventy-one bee pollen samples from four different apiaries was determined by means of inductively coupled plasma-optical emission spectrometry. The results showed that there were no significant differences in relation to the overall mineral content per sample in terms of the apiary of origin or the harvesting period; the most common elements were phosphorus and potassium with concentrations ranging from 2.3 to 5.1 g/kg (dry weight). Moreover, the mineral content of the samples analyzed was similar to or higher than the recommended as well-balanced food for bees. Regarding the nutritional value for humans, bee pollen samples could be considered as a food rich in copper, iron, magnesium, manganese, and phosphorus. Finally, a canonical discriminant analysis was performed, and it was found that the apiary of origin could be distinguished by using the first three canonical functions; furthermore, over 90% of the samples could be correctly assigned to their corresponding apiary. The results were even better as regards the harvesting period, as only the first two canonical functions were sufficient to make a distinction between the different harvesting periods, resulting in a perfect match (100% of success rate).Ministerio de Economía y Competitividad (RTI2018-096268-B-100)Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (RTA 2015-00013-C03-01 and 03)FEDER and FSE (project AGRISOST-CM S2018/BAA-4330

    Palaeolithic rock art in Alkerdi 2 cave (Urdazubi/Urdax, Navarra)

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    En el marco del proyecto de «Caracterización del macizo y sistema kárstico de Alkerdi,de la cueva de Alkerdi y de su entorno de protección», se procede a la exploración de la cavidad de Alkerdi 2. Las labores coordinadas han permitido identificar un conjunto de arte parietal asociado a evidencias arqueológicas en superficie. El estilo de las grafías animales grabadas apunta hacia una atribución Gravetiense para la presencia humana. La datación por radiocarbono de uno de los motivos parietales y de un carbón procedente del contexto arqueológico, lo corroboran. Se trata así de la segunda cavidad decorada durante el Paleolítico en Navarra y la muestra artística más antigua de la Comunidad Foral.Within the framework of the characterization project of the massif and karst system of Alkerdi, the Alkerdi cave and its protective environment, the Alkerdi 2 cavity was explored. The coordinated work has made it possible to identify a set of parietal art associated with archaeological evidence on the surface. The style of the engraved animal points towards a Gravettian attribution for human presence. Radiocarbon dating of one of the parietal motifs and a charcoal from the archaeological context corroborate this idea. This is the second cavity decorated during the Paleolithic in Navarre and the oldest artistic remain in the Autonomous Community

    First results from the AugerPrime Radio Detector

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    Update of the Offline Framework for AugerPrime

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    Outreach activities at the Pierre Auger Observatory

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    The ultra-high-energy cosmic-ray sky above 32 EeV viewed from the Pierre Auger Observatory

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