572 research outputs found

    Pellet analysis evidences flexibility in the diet of Brown Skua (Stercorarius antarcticus) during breeding at Esperanza/Hope Bay (Antarctic Peninsula)

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    At Esperanza/Hope Bay, Antarctic Peninsula, breeding Brown Skuas (Stercorarius antarcticus) coexist with a breeding colony of Adélie (Pygoscelis adeliae) and Gentoo (P. papua) penguins. Previously, we reported that the principal prey consumed by Brown Skuas was penguin, however, the contribution of marine resources to their diet was high. Besides, the number of conspecifics that compete for this resource gradually increases across the season. This prompted us to enquire into the ecological factors that may promote the use of marine resources during the breeding cycle. For this, during the 2014–2015 and 2015–2016 seasons, 400 regurgitated pellets were collected over the breeding season for different stages in the nesting cycle: incubation, early and late chick rearing. Prey items were classified according to different categories (penguin, fish, mollusk, and crustacea), and the occurrence frequency of each category was determined. As expected, penguins were the main prey consumed, but the occurrence of fish and mollusks increased for both early and late care of chicks. The flexibility in skua foraging behavior may be related to the changing degree of central place forager, and to the fluctuating energy requirements during each breeding stage. Moreover, the conspicuous decline in penguin availability or accessibility induced by intraspecific competition, may represent an alternative driving force in their foraging behavior over the breeding season.Fil: Ibañez, Andres Esteban. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Morales, Lara Mariel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Torres, D. S.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; ArgentinaFil: Borghello, P.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; ArgentinaFil: Montalti, Diego. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentin

    Solid phase microextraction techniques used for gas chromatography: A review

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    In the last decade, the development and adoption of greener and sustainable microextraction techniques have been proved to be an effective alternative to classical sample preparation procedures. In this review, 10 commercially available solid-phase microextraction systems are presented, with special attention to the appraisal of their analytical, bioanalytical, and environmental engineering. This review provides an overview of the challenges and achievements in the application of fully automated miniaturized sample preparation methods in analytical laboratories. Both theoretical and practical aspects of these environment-friendly preparation approaches are discussed. The application of chemometrics in method development is also discussed. We are convinced that green analytical chemistry will be really useful in the years ahead. The application of cheap, fast, automated, clever , and environmentally safe procedures to environmental, clinical, and food analysis will improve significantly the quality of the analytical data

    Liquid phase microextraction techniques combined with chromatography analysis: A review

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    Sample pretreatment is the first and the most important step of an analytical procedure. In routine analysis, liquid-liquid microextraction (LLE) is the most widely used sample pre-treatment technique, whose goal is to isolate the target analytes, provide enrichment, with cleanup to lower the chemical noise, and enhance the signal. The use of extensive volumes of hazardous organic solvents and production of large amounts of waste make LLE procedures unsuitable for modern, highly automated laboratories, expensive, and environmentally unfriendly. In the past two decades, liquid-phase microextraction (LPME) was introduced to overcome these drawbacks. Thanks to the need of only a few microliters of extraction solvent, LPME techniques have been widely adopted by the scientific community. The aim of this review is to report on the state-of-the-art LPME techniques used in gas and liquid chromatography. Attention was paid to the classification of the LPME operating modes, to the historical contextualization of LPME applications, and to the advantages of microextraction in methods respecting the value of green analytical chemistry. Technical aspects such as description of methodology selected in method development for routine use, specific variants of LPME developed for complex matrices, derivatization, and enrichment techniques are also discussed

    Kinetic cross-modal correspondences and felt (e)motion in a novel set of musical stimuli

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    Embodied music cognition predicts that our understanding of human-made sounds relates to our experience of making the same or similar movements and sounds, which involves imitation of the source of visual and auditory information. This embodiment of sound may lead to numerous kinetic cross-modal correspondences (CMCs). This article investigates music experience in participants with a non-professionally trained music background across three musical dimensions: Contour (Ascending, Descending, Flat), Vertical Density (Low, Medium, High), and Note Pattern (Binary, Ternary, Quaternary). In order that stimuli should reflect contemporary musical usage yet be subject to a high degree of experimental control, 27 ten-second digital piano tracks were created in collaboration with a film composer. In Study 1, participants were asked to rate the stimuli for perceived Direction, Rotation, Movement, and Emotional and Physical Involvement. We test the effects of these factors in terms of the following theories: general and vocal embodied responses to music, the Ecological Theory of Rotating Sounds, and the Shared Affective Motion Experience model of emotion induction. Results for Study 1 were consistent with theories of general and vocal embodied responses to music, as well as with theories of embodied emotional contagion in music. Study 1 also revealed potential confounds in the stimuli, which were further investigated in Study 2 with a new set of participants rating the stimuli for perceived Pitch, Loudness, and Speed. Results for Study 2 served to dissociate intrinsic features of the stimuli from CMCs. Taken together, the two studies reveal a range of embodied CMCs. Although there are limitations to a perceptual study such as this, these stimuli stand to benefit future research in further investigating the embodiment of musical motion

    El estornino pinto en Argentina: desafíos y prioridades

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    El día 11 de septiembre de 2015 se desarrolló la mesa redonda “Invasión del estornino pinto (Sturnus vulgaris) en Argentina”, en el marco de la XVI Reunión Argentina de Ornitología organizada por la Sección Ornitología del Museo de La Plata (Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata). En esa oportunidad se informó acerca de las características de la especie, de las consecuencias de su introducción en distintos países, del estado actual de la invasión en Argentina y de los antecedentes relacionados con su control. Además, se realizó una actividad en la que los participantes propusieron medidas de acción prioritarias para el manejo de la especie a nivel local, regional y nacional. En esta contribución resumimos los aspectos más relevantes de la reunión y las conclusiones de la misma
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