2,020 research outputs found

    The global carbon cycle and its changes over glacial–interglacial cycles

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    Carbon is an essential element for life, food and energy. It is also a key component of greenhouse gases and, thus, plays an important role in past and present climatic changes

    A new geodynamic interpretation for the South Portuguese Zone (SW Iberia) and the Iberian Pyrite Belt genesis.

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    International audienceThe South Portuguese Zone (SPZ) constitutes the southernmost segment of the Variscan Iberian Massif. It is bounded to the north by the Beja-Acebuches Ophiolitic Complex and related accretionary wedge. To the south lie the Iberian Pyrite Belt (IPB) and flysch deposits forming the southern extent of the zone. Structural analysis within the Spanish side of the SPZ supports continuous south propagating deformation, evolving from early synmetamorphic thrusting in the internal zone to thin-skinned tectonics in the southern external domain. The accretion of the SPZ to the Ossa Morena Zone is also witnessed by the presence of various mélanges, observed throughout the investigated area. Part of the mélanges observed in the IPB are related to the volcanics and mineralizations setting. A key point to understand the IPB mineralizations genesis is to constrain the volcanogenic model. One underestimated feature is the large amount of submarine calc-alkaline ignimbritic facies, implying the presence of caldera structures within the province. Such correlation between caldera environment and ore deposits strongly suggests that the IPB developed in a continental arc. Our geodynamic model proposes an early north directed subduction associated with the obduction of the oceanic crust toward the south. Southward, this episode is immediately followed by the development of the accretionary prism, while farther south, a second subduction zone responsible for the arc setting of the IPB initiates. Subsequent Visean continental collision is associated with the deposit of the south propagating flysch and the present geometry of the SPZ

    Relevance of Lipid-Based Products in the Management of Dry Eye Disease

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    Components of the ocular surface synergistically contribute to maintaining and protecting a smooth refractive layer to facilitate the optimal transmission of light. At the air-water interface, the tear film lipid layer (TFLL), a mixture of lipids and proteins, plays a key role in tear surface tension and is important for the physiological hydration of the ocular surface and for ocular homeostasis. Alterations in tear fluid rheology, differences in lipid composition, or downregulation of specific tear proteins are found in most types of ocular surface disease, including dry eye disease (DED). Artificial tears have long been a first line of treatment in DED and aim to replace or supplement tears. More recently, lipid-containing eye drops have been developed to more closely mimic the combination of aqueous and lipid layers of the TFLL. Over the last 2 decades, our understanding of the nature and importance of lipids in the tear film in health and disease has increased substantially. The aim of this article is to provide a brief overview of our current understanding of tear film properties and review the effectiveness of lipid-based products in the treatment of DED. Liposome lid sprays, emulsion eye drops, and other lipid-containing formulations are discussed.Peer reviewe

    Data Filtering in the readout of the CMS Electromagnetic Calorimeter

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    For an efficient data taking, the Electromagnetic Calorimeter (ECAL) data of the CMS experiment must be limited to 10\% of the full event size (1MB). Other requirements limit the average data size to 2kB per data acquisition link. These conditions imply a reduction factor of close to twenty on the data collected. The data filtering in the readout of the ECAL detector is discussed. Test beam data are used to study the digital filtering applied in the readout channels and a full detector simulation allows to estimate the energy thresholds to achieve the desired data suppression factor

    Laser monitoring system for the CMS lead tungstate crystal calorimeter

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    We report on the multiple wavelength laser monitoring system designed for the CMS lead tungstate crystal calorimeter read-out with avalanche photodiodes (Barrel calorimeters) and vacuum phototriodes (End Cap calorimeters). Results are presented for the test beam performance of the system designed to achieve 0.5% relative inter-calibration of the optical transmittance for lead tungstate scintillation emission over nearly 80 000 channels. The system operates in continuous measurement cycles to follow each crystal?s evolution under irradiation and recovery periods foreseen during operation at the LHC

    Nipah Virus in Lyle's Flying Foxes, Cambodia

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    We conducted a survey in Cambodia in 2000 on henipavirus infection among several bat species, including flying foxes, and persons exposed to these animals. Among 1,072 bat serum samples tested by enzyme-linked immunosorbent assay, antibodies reactive to Nipah virus (NiV) antigen were detected only in Pteropus lylei species; Cynopterus sphinx, Hipposideros larvatus, Scotophilus kuhlii, Chaerephon plicata, Taphozous melanopogon, and T. theobaldi species were negative. Seroneutralization applied on a subset of 156 serum samples confirmed these results. None of the 8 human serum samples was NiV seropositive with the seroneutralization test. One virus isolate exhibiting cytopathic effect with syncytia was obtained from 769 urine samples collected at roosts of P. lylei specimens. Partial molecular characterization of this isolate demonstrated that it was closely related to NiV. These results strengthen the hypothesis that flying foxes could be the natural host of NiV. Surveillance of human cases should be implemented

    Review. Divergent selection for residual feed intake in the growing pig

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    To view supplementary material for this article, please visit https:/doi.org/10.1017/S175173111600286XThis review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant ( P<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses wereobserved on growth rate (−12.8 g/day, P <0.05) and body composition (+0.9mm backfat thickness, P = 0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat ( P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors,via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory

    When East Meets West: International Change and Its Effects on Domestic Cultural Institutions

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    Domestic governments increasingly face the pressure to follow policy developments occurring at the international or supranational level. Yet international laws and policies need to be “translated” to suit domestic political institutions and newly adopted policies may challenge or contradict preexisting domestic policies, institutions, and interests. To explore the domestic impact of international institutional developments, we studied the United Nations Educational, Scientific, and Cultural Organization (UNESCO) Convention for the Safeguarding of Intangible Cultural Heritage and its adoption in four countries (Japan, China, France, and Germany). Using historical institutionalism, this comparative case study sheds light on the effects of the Convention on cultural governance systems in two supposedly different “camps” within the UNESCO: the East and the West. The study argues that it is the interaction and entangled relationship of exogenous and endogenous factors over time, particularly the timing and sequence in which they constrain and facilitate change, which shape actors’ preferences and institutional development at both levels