3,644 research outputs found

    Integration of temporal environmental variation by the marine plankton community

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    Theory and observations suggest that low frequency variation in marine plankton populations, or red noise, may arise through cumulative integration of white noise atmospheric forcing by the ocean and its amplification within food webs. Here, we revisit evidence for the integration of stochastic atmospheric variations by comparing the power spectra of time series of atmospheric and oceanographic conditions to the population dynamics of 150 plankton taxa at Station L4 in the Western English Channel. The power spectra of oceanographic conditions (sea surface temperature, surface nitrate) are redder than those of atmospheric forcing (surface wind stress, net heat fluxes) at Station L4. However, plankton populations have power spectral slopes across trophic levels and body sizes that are redder than atmospheric forcing but whiter than oceanographic conditions. While zooplankton have redder spectral slopes than phytoplankton, there is no significant relationship between power spectral slope and body size or generation length. Using a predator−prey model, we show that the whitening of plankton time series relative to oceanographic conditions arises from noisy plankton bloom dynamics in this strongly seasonal system. The model indicates that, for typical predator−prey interactions, where the predator is on average 10 times longer than the prey, grazing leads to a modest reddening of phytoplankton variability by their larger and longer lived zooplankton consumers. Our findings suggest that, beyond extrinsic forcing by the environment, predator–prey interactions play a role in influencing the power spectra of time series of plankton populations

    JUAN DE LA CRUZ JUNTO A ANCIANA VESTIDA DE CAMPESINA [Material gráfico]

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    ADQUIRIDA POR EL COLECCIONISTA EN TENERIFE.FOTO COLOR DE JUAN DE LA CRUZ JUNTO A ANCIANA VESTIDA DE CAMPESINACopia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

    JUAN DE LA CRUZ JUNTO A ANCIANA VESTIDA DE CAMPESINA [Material gráfico]

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    ADQUIRIDA POR EL COLECCIONISTA EN TENERIFE.FOTO COLOR DE JUAN DE LA CRUZ JUNTO A ANCIANA VESTIDA DE CAMPESINACopia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

    CAMPESINA CON MANTA Y SOMBRERO DE MAGA [Material gráfico]

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    FOTO COLOR DE RETRATO DE ANCIANA VESTIDA DE CAMPESINA CON MANTA Y SOMBRERO DE MAGATIENE VALOR ETNOGRÁFICO. ERA LA ÚLTIMA ANCIANA DE TENERIFE QUE USABA EL SOMBRERO DE MAGA. ADQUIRIDA POR EL COLECCIONISTA EN TENERIFE.Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

    Reconstructing North Atlantic marine climate variability using an absolutely-dated sclerochronological network

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    This is the final version of the article. Available from Elsevier via the DOI in this record.Reconstructing regional to hemispheric-scale climate variability requires the application of spatially representative and climatically sensitive proxy archives. Large spatial networks of dendrochronologies have facilitated the reconstruction of atmospheric variability and inferred variability in the Atlantic Ocean system. However, the marine environment has hitherto lacked the direct application of the spatial network approach because of the small number of individual absolutely-dated marine archives. In this study we present the first analyses of a network of absolutely-dated annually-resolved growth increment width chronologies from the marine bivalves Glycymeris glycymeris and Arctica islandica. The network contains eight chronologies spanning > 500 km along the western British continental shelf from the southern Irish Sea to North West Scotland. Correlation analysis of the individual chronologies and a suite of climate indices, including the Atlantic Multidecadal Oscillation (AMO), Central England surface air temperature (CET), northeast Atlantic sea surface temperatures (SST's) and the winter North Atlantic Oscillation (wNAO), demonstrates that, despite the large geographical distances been sites and the heterogeneous nature of the marine environment, the increment width variability in these series contains an element of coherence likely driven by a common response to changing environmental forcing. A nested Principal component analysis (PCA) was used to construct five composite series which explain between 31% and 74% of the variance across the individual chronologies. Linear regression analyses indicate that the composite series explain up to 41% of the variance in Northeast Atlantic SSTs over the calibration period (1975–2000). Calibration verification (reduction of error [RE] and coefficient of efficiency [CE]) statistics indicate that the composite series contains significant skill at reconstructing multi-decadal northeast Atlantic SST variability over the past two centuries (1805–2010). These data suggest that composite series derived from sclerochronology networks can facilitate the robust reconstruction of marine climate over past centuries to millennia providing invaluable baseline records of natural oceanographic variability.This work was supported financially by the NERC funded project Climate of the Last Millennium Project (CLAM; project No. NE/N001176/1) and the Marie Curie Frame work Partnership Annually Resolved Archives of Marine Climate Change (ARAMACC; Project No. FP7 604802). The authors would like to thank the three anonymous reviewer‘s for their constructive comments during the peer review process

    A Pathway From Porous Particle Technology Toward Tailoring Aerogels for Pulmonary Drug Administration

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    Pulmonary drug delivery has recognized benefits for both local and systemic treatments. Dry powder inhalers (DPIs) are convenient, portable and environmentally friendly devices, becoming an optimal choice for patients. The tailoring of novel formulations for DPIs, namely in the form of porous particles, is stimulating in the pharmaceutical research area to improve delivery efficiency. Suitable powder technological approaches are being sought to design such formulations. Namely, aerogel powders are nanostructured porous particles with particularly attractive properties (large surface area, excellent aerodynamic properties and high fluid uptake capacity) for these purposes. In this review, the most recent development on powder technologies used for the processing of particulate porous carriers are described via updated examples and critically discussed. A special focus will be devoted to the most recent advances and uses of aerogel technology to obtain porous particles with advanced performance in pulmonary delivery.Work carried out in the framework of COST Action CA18125 “Advanced Engineering and Research of aeroGels for Environment and Life Sciences” (AERoGELS), funded by the European Commission. This work was also supported by Xunta de Galicia [ED431C 2020/17], MCIUN [RTI2018-094131-AI00], Agencia Estatal de Investigación [AEI], and FEDER funds. CG-G acknowledges to MINECO for a Ramón y Cajal Fellowship [RYC2014-15239]

    Vida y hechos del maestro Don Alonso Tostado de Madrigal, Obispo de Auila ...

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    Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 2007Sign.: []2, A-I4Port. con esc. calc. heráldic

    Saynete nuevo Intitulado El gitano Canuto Mojarra o El dia de toros en Sevilla : para trece personas

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    Fernández Gómez, Juan F. Catálogo de entremeses y sainetes del siglo XVIII, 654El autor es Juan Ignacio González del CastilloDía de toros en CádizPrecede al tít.: "190.

    Applications of Direct Injection Soft Chemical Ionisation-Mass Spectrometry for the Detection of Pre-blast Smokeless Powder Organic Additives

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    Analysis of smokeless powders is of interest from forensics and security perspectives. This article reports the detection of smokeless powder organic additives (in their pre-detonation condition), namely the stabiliser diphenylamine and its derivatives 2-nitrodiphenylamine and 4-nitrodiphenylamine, and the additives (used both as stabilisers and plasticisers) methyl centralite and ethyl centralite, by means of swab sampling followed by thermal desorption and direct injection soft chemical ionisation-mass spectrometry. Investigations on the product ions resulting from the reactions of the reagent ions H3O+ and O2+ with additives as a function of reduced electric field are reported. The method was comprehensively evaluated in terms of linearity, sensitivity and precision. For H3O+, the limits of detection (LoD) are in the range of 41-88 pg of additive, for which the accuracy varied between 1.5 and 3.2%, precision varied between 3.7 and 7.3% and linearity showed R20.9991. For O2+, LoD are in the range of 72 to 1.4 ng, with an accuracy of between 2.8 and 4.9% and a precision between 4.5 and 8.6% and R20.9914. The validated methodology was applied to the analysis of commercial pre-blast gun powders from different manufacturers.(VLID)4826148Accepted versio
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