724 research outputs found

    Is Orienting of Attention Selectively Impaired After Sleep Loss? The Role of Disengagement

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    Research on the effects of sleep deprivation on covert orienting of attention have produced evidence indicating either a negative or a null impact of sleep loss. Moreover, it is still unclear whether, following sleep deprivation, there is a general impairment of orienting processes or a selective one. Aim of the present study is highlighting the effects of sleep deprivation on the three subcomponents of orienting of attention: disengagement, moving and engagement (Posner and Raichle, 1994). The ANT-R (Fan et al., 2009) was administered following two sleep conditions: Baseline - a regular night of uninterrupted sleep, and Deprivation - 24 hours of total sleep deprivation. We have found a significant slowing down of the disengagement component, while engagement and shift components were virtually unaffected by sleep deprivation. Our data show that sleep deprivation selectively affects the three subcomponents underlying covert orienting of attention. Hence, they suggest that performance deficits following sleep curtailment should no longer be accounted for in terms of a general reduction of alertness or global attentional deficits

    Sleep deprivation selectively impairs attentional networks.

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    Efectos perjudiciales de la deposición de ceniza volcánica en abejas y en las interacciones planta-polinizador

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    Volcanic eruptions are large-scale natural disturbances, which can negatively affect insect fauna and the ecological interactions in which they are involved. The 2011 eruption of the volcanic complex Puyehue Cordón-Caulle (PCC) produced the deposition of 950 million tons of ash on Argentine Patagonia, creating an ash layer of varying thickness. Although experimental studies confirmed that PCC volcanic ash negatively affects survival and behavior in many insect taxa, including bees, the effects of ash deposition on the plant-pollinator interactions (PPI) of this group of insects in natural landscapes remained untested. We evaluated the effect of the gradient of increasing ash layer thickness (0-15cm) on: (1) number of wild bees visiting flowers and total bee richness in 16 raspberry fields after the eruption, (2) number of native (Bombus dahlbomii) and invasive (B. terrestris and B. ruderatus) bumble bees foraging on wild flowers in 10 sites before and after the eruption, and (3) the proportion of “triggered” flowers (i.e. papilionaceous flowers visited for first time by large bees) in 32 populations of the invasive shrub scotch broom (Cytisus scoparius), before and after the eruption. With the increase of ash deposition, we found a consistent and significant decrease in (1) the number of wild bees and total bee richness visiting raspberry flowers; (2) the number of bumble bees, particularly B. terrestris, visiting wild flowers; and (3) the proportion of triggered flowers of scotch broom. Thus, volcanic eruptions can exert a detrimental effect on bee fauna and concomitant PPI, with a potential cascade effect on the pollination service to crops, the spread of invasive bumble bees, and the pollination success of invasive plants.Las erupciones volcánicas son perturbaciones naturales a gran escala, que pueden afectar negativamente a la fauna de insectos y las interacciones ecológicas en las que están involucrados. La erupción del complejo volcánico Puyehue Cordón-Caulle (PCC) en el 2011 depositó 950 millones de toneladas de cenizas en la Patagonia Argentina, creando una capa de cenizas de espesor variable. Si bien los estudios experimentales confirmaron que las cenizas del PCC afectan negativamente la supervivencia y el comportamiento en varios taxones de insectos, incluidas las abejas, el efecto de la deposición de ceniza en las interacciones planta-polinizador (IPP) asociadas a éstas últimas no ha sido investigado en paisajes naturales. Evaluamos el efecto del gradiente de creciente grosor de la capa de cenizas (0-15 cm.) en: (1) el número de abejas silvestres visitando flores de frambuesa y riqueza total de abejas en 16 campos, (2) el número de abejorros nativos (Bombus dahlbomii) e invasores (B. terrestris y B. ruderatus) forrajeando en flores silvestres en 10 sitios, y (3) la proporción de las flores “disparadas” (flores papilionáceas visitadas por primera vez por abejas de gran tamaño) en 32 poblaciones del arbusto invasor Cytisus scoparius (retama). Con el aumento en el espesor de la capa de ceniza, encontramos una fuerte y consistente disminución de: (1) el número de abejas silvestres y la riqueza de abejas totales en flores de frambuesa; (2) el número de abejorros, en particular de B. terrestris, visitando flores silvestres; y (3) la proporción de flores de retama disparadas. Las erupciones volcánicas pueden afectar fuertemente a la fauna de abejas y las interacciones planta-polinizador, con posibles efectos en cascada sobre el servicio de polinización de cultivos, la expansión de abejorros invasores y el éxito de polinización de una planta invasora.Fil: Morales, Carolina Laura. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Sáez, Agustín. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Arbetman, Marina P.. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina. Universidad Nacional de Rio Negro. Sede Andina; ArgentinaFil: Cavallero, Laura. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Aizen, Marcelo Adrian. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentin

    Presbyphagia and dysphagia in old age

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    Although presbyphagia is a clinically relevant problem among elderly population, possibly leading to dysphagia in old age, it remains a still underestimated health condi-tion. The present review analyzes swallow-ing related anatomical and functional changes during aging, both in healthy peo-ple and in those affected by dysphagia. First of all, dysphagia in old people must not be confused with presbyphagia. To distinguish these two different conditions, a correct def-inition of both should be considered. Subsequently, a comprehensive evaluation including instrumental analysis should be carried out. The aim of this narrative review is to analyze the current knowledge of this clinical condition and to provide the state of art to clinicians. A systematic PubMed research on dysphagia in the elderly was conducted and most relevant and most recent references were manually screened and selected. The aim of a correct diagnosis is to enable the choice of a correct interven-tion in order to prevent and treat complica-tions of dysphagia, such as ab ingestis pneumonia and malnutrition. Moreover, the assessment, diagnosis and therapy of dys-phagia/presbyphagia should include the intervention of different specialists

    Retention and redistribution of biological legacies generate resource sinks in silvopastoral systems of Arid Chaco forests

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    Background: Forests are used for multiple purposes worldwide, which often include timber harvest, firewood extraction and livestock raising. An excessive pressure on multipurpose systems may decrease soil cover, promoting soil erosion and causing the loss of other resources, as litter and seeds. Retention forestry practices can help to decrease or mitigate resource loss in the managed stands. Specifically, retaining and redistributing biological legacies (e.g. logs, branches, woody debris) at strategic locations can create sediment, litter, and seed-sinks in the silvopastoral systems. In addition, grazing management could increase or, even, decrease the success of this practice. In this study, we assessed the effect of branch barriers and grazing management on resource run-off/runon processes in silvopastoral systems of Arid Chaco (Córdoba, Argentina). To do this, a 2-ha area was divided in two paddocks that were randomly assigned to different grazing managements: winter vs. continuous grazing. We randomly selected 22 water run-off paths in each paddock, and in the half of them, we build elongated branch piles. In each run-off path (with and without branch barriers), we recorded the amount of accumulated and lost sediment (during the rainy season), litter biomass, germinable seed bank, richness and cover of plant species, and richness and density of seedlings and saplings of woody species. Results: Branch barriers promoted sediment accumulation during the first and the second year of the study, depending on grazing management. The temporal and spatial scale of the effect of the branch barriers also depended on grazing management. Branch barriers also trapped litter and seeds, which may have increased the richness and density of seedlings and saplings of woody species. Conclusions: By intercepting the dominant flow of erosive agents, branch barriers trapped sediment, litter, and propagules of different species. A greater amount of sediment and litter would have improved microsite quality, favouring seed germination and seedling emergence of tree and shrub species, which are key to maintain and/ or reconstitute the structure and composition of the forest community in the long term. Therefore, redistributing biological legacies at strategic locations can be a useful and cost-less retention forestry practice to be applied in multipurpose forest management and conservation strategies.Fil: Cavallero, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; ArgentinaFil: Ledesma, Marcela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; ArgentinaFil: López, Dardo Rubén. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; ArgentinaFil: Carranza, Carlos Andrés. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; Argentin

    Morphological variation of the leaves of Aechmea distichantha Lem. plants from contrasting habitats of a Chaco forest: a trade-off between leaf area and mechanical support

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    Several authors have reported phenotypic plasticity for bromeliad plants growing in contrasting habitats. Morphological and physiological differences of leaves seem to be an adaptation to water and light use, but there is also a compromise between carbon gain and the costs of sustaining static and dynamic loads. We hypothesized that plastic responses to habitat at the leaf level represent a trade-off between the photosynthetic area for capturing light and mechanical support. In this study, we measured morphological and architectural variables of central and basal leaves of Aechmea distichantha plants from the understory and forest edge, as well as anatomical variables of plants from each habitat. Understory plants had longer leaves, larger blade areas and greater length/width ratios than forest-edge plants. Blades of understory plants were less erect, less succulent, had thicker fiber tissue surrounding the vascular bundles and a higher curvature index than blades of forest-edge plants. Thus, understory plants increased their flexural stiffness by modifying their tissue structure as well as the shape of their leaves. On the other hand, blades of forest-edge plants had higher stomatal density and higher trichome density on their adaxial sides than understory plants. These patterns could be adaptations for higher gas exchange and to reduce vulnerability to photoinhibition in sun plants when compared to shade plants. Finally, most of the morphological and architectural variables were significantly different between positions. These results support our view that there is a trade-off at the leaf level between photosynthetic leaf area (for light capture and water use) and mechanical support

    A survey on the occurrence of ochratoxin A in feeds and sera collected in conventional and organic poultry farms in Northern Italy

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    A survey has been conducted on conventional and organic poultry farms located in northern Italy in order to investigate the occurrence of ochratoxin A (OTA) in feeds and sera in 2006. Ten poultry farms were monitored by taking 20 samples of feed and 94 samples of blood. OTA was assessed through immunoaffinity column purification and HPLC analysis. For in-house validation, recovery experiments, carried out on the spiked samples in the range of 1.0-10.0 μg OTA kg-1 and 0.3-3.0 ng OTA ml-1 for the feed and serum samples, respectively, led to overall recovery averages of 80.6% (RDS=7.3%, n=9) and 83.3% (RDS=3.1%, n=9), respectively. All the feed samples were contaminated by OTA with values ranging from 0.04 to 6.50 μg kg-1. Fiftythree percent of the sera samples were positive, with values ranging from 0.003- 0.165 ng ml-1. None of the feed samples was above the limits set by the European Union on OTA contamination in poultry feeds. No statistically significant differences in OTA contamination of feed or sera were observed either between the organic vs conventional group or between the laying hens vs broiler group

    Spatial and temporal phylogeny of border disease virus in pyrenean chamois (Rupicapra p. Pyrenaica)

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    Border disease virus (BDV) affects a wide range of ruminants worldwide, mainly domestic sheep and goat. Since 2001 several outbreaks of disease associated to BDV infection have been described in Pyrenean chamois (Rupicapra pyrenaica pyrenaica) in Spain, France and Andorra. In order to reconstruct the most probable places of origin and pathways of dispersion of BDV among Pyrenean chamois, a phylogenetic analysis of 95 BDV 5'untranslated sequences has been performed on chamois and domestic ungulates, including novel sequences and retrieved from public databases, using a Bayesian Markov Chain Monte Carlo method. Discrete and continuous space phylogeography have been applied on chamois sequences dataset, using centroid positions and latitude and longitude coordinates of the animals, respectively. The estimated mean evolutionary rate of BDV sequences was 2.9x10(-3) subs/site/year (95% HPD: 1.5-4.6x10(-3)). All the Pyrenean chamois isolates clustered in a unique highly significant clade, that originated from BDV-4a ovine clade. The introduction from sheep (dated back to the early 90s) generated a founder effect on the chamois population and the most probable place of origin of Pyrenean chamois BDV was estimated at coordinates 42.42 N and 1.9 E. The pathways of virus dispersion showed two main routes: the first started on the early 90s of the past century with a westward direction and the second arise in Central Pyrenees. The virus spread westward for more than 125 km and southward for about 50km and the estimated epidemic diffusion rate was about 13.1 km/year (95% HPD 5.2-21.4 km/year). The strong spatial structure, with strains from a single locality segregating together in homogeneous groups, and the significant pathways of viral dispersion among the areas, allowed to reconstruct both events of infection in a single area and of migrations, occurring between neighboring areas

    Ordenamiento Ambiental de Bosques y Ecosistemas Asociados para el desarrollo sustentable en el ejido del Municipio del Nono, Valle Traslasierra, Córdoba.Argentina

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    La dimensión del paisaje actual de una población de la serranía cordobesa, con su tejido urbano entremezclado con ríos y bosques, hace pensar que es un hábitat sustentable en el hoy y en el futuro, pero conflictos socio-ambientales muestran la necesidad de acciones de planificación que sus dirigentes tienen que gestionar. La tarea de aportar herramientas de ordenamiento territorial, que faciliten la creación de normativas tendientes a proteger y proyectar usos del ambiente con sus cuencas, bosques, corredores de fauna y recursos naturales que den identidad a la población existente y futura del Municipio de Nono, dan el sentido a ésta publicación. La misma describe y provee información, la cual podrán tomar como respaldo en sus gestiones, los dirigentes políticos actuales y futuros del municipio. Desde el equipo de INTA conjuntamente con otras instituciones y actores, consolidaron ésta publicación que invitamos a leer y compartir con compañeros y personas comprometidas con la inserción de comunidades en paisajes, que desde la belleza tangible, sostengan la imagen de uso perdurable para generaciones futurasEEA ManfrediFil: Cavallero, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Centro Científico Tecnológico Córdoba; ArgentinaFil: Cavallero, Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; ArgentinaFil: Mari, Nicolás A. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Agencia de Extensión Rural Cruz del Eje; ArgentinaFil: Carranza, Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; Argentin
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