1,056 research outputs found

    Measure of National Return in International Science Cooperation

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    In the decades since science and technology measures were crafted and adopted by governments, R&D has increasingly taken place across national boundaries. This leaves a gap for policy makers in how to account for the benefits to national governments of supporting international collaboration in science. This article seeks to address this gap by suggesting a measure for the impact of international collaboration in science using fractionalized field-weighted citations and analysing these in relationship to public spending and researcher mobility

    In vivo postprandial lipid partitioning in liver and muscle of diabetic rats is disturbed

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    Objective: To study in vivo lipid partitioning in insulin-resistant liver and muscle of diabetic rats using magnetic resonance spectroscopy (MRS). Methods: Four groups of n=6 male Zucker diabetic fatty rats were used for this study: obese, pre-diabetic fa/fa rats and lean, non-diabetic fa/+ littermates at the age of 6 weeks, and obese, diabetic fa/fa rats and lean, non-diabetic fa/+ littermates at the age of 12 weeks. 1H-[13C] MRS measurements were performed in liver and tibialis anterior muscle at baseline and 4, 24 and 48 h after oral administration of 1.5 g [U-13C] Algal lipid mixture per kg body weight. Results: At baseline, total lipid content was higher in fa/fa rats compared with fa/+ rats in both liver and muscle, and at both ages. Both in pre-diabetic and in diabetic fa/fa rats, hepatic lipid uptake was increased compared with non-diabetic fa/+ rats. Likewise, in muscle of diabetic fa/fa rats, lipid uptake was higher than in muscle of fa/+ rats. In contrast, lipid uptake in muscle of younger, pre-diabetic fa/fa rats was lower than in controls. Conclusion: In the pre-diabetic state, muscle appeared to be protected from massive lipid uptake, whereas lipid uptake in the liver was largely increased. In contrast, after developing full-blown diabetes, lipid uptake was highly elevated in both liver and muscle. This research was funded by a VIDI grant from the Netherlands Organisation for Scientific Research (NWO)

    Levels of Abstractness in Semantic Noun and Verb Processing:The Role of Sensory‑Perceptual and Sensory‑Motor Information

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    Effects of concreteness and grammatical class on lexical-semantic processing are well-documented, but the role of sensory-perceptual and sensory-motor features of concepts in underlying mechanisms producing these effects is relatively unknown. We hypothesized that processing dissimilarities in accuracy and response time performance in nouns versus verbs, concrete versus abstract words, and their interaction can be explained by differences in semantic weight—the combined amount of sensory-perceptual and sensory-motor information to conceptual representations—across those grammatical and semantic categories. We assessed performance on concrete and abstract subcategories of nouns and verbs with a semantic similarity judgment task. Results showed that when main effects of concreteness and grammatical class were analyzed in more detail, the grammatical-class effect, in which nouns are processed more accurately and quicker than verbs, was only present for concrete words, not for their abstract counterparts. Moreover, the concreteness effect, measured at different levels of abstract words, was present for both nouns and verbs, but it was less pronounced for verbs. The results do not support the grammatical-class hypothesis, in which nouns and verbs are separately organized, and instead provide evidence in favor of a unitary semantic space, in which lexical-semantic processing is influenced by the beneficial effect of sensory-perceptual and sensory-motor information of concepts

    Magnetoresistance of a semiconducting magnetic wire with domain wall

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    We investigate theoretically the influence of the spin-orbit interaction of Rashba type on the magnetoresistance of a semiconducting ferromagnetic nanostructure with a laterally constrained domain wall. The domain wall is assumed sharp (on the scale of the Fermi wave length of the charge carriers). It is shown that the magnetoresistance in such a case can be considerably large, which is in a qualitative agreement with recent experimental observations. It is also shown that spin-orbit interaction may result in an increase of the magnetoresistance. The role of localization corrections is also briefly discussed.Comment: 5 pages, 2 figure

    In vivo magnetic resonance spectroscopy of lipid handling in steatotic rat liver

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    Objective: Examine lipid handling in liver of rats fed with different high-fat diets using 1H-[13C] magnetic resonance spectroscopy (MRS) together with oral administration of 13C labeled lipids. Methods: 6 male Wistar rats (11 weeks old; 348 ± 8g) were divided into three diet groups: low-fat (10% fat, CON), high-fat lard (45% fat, HFL), and high-fat palm oil (45%, HFP). After 10 weeks of diet, MRS experiments were performed at baseline, and 4 and 24 h after oral administration of 1.5 g [U-13C] Algal lipid mixture per kg body weight. Results: At 4 h after administration of the 13C labeled lipids, 13C enrichment of intracellular liver lipids was similarly increased in all three groups compared to baseline (CON: 0.031 ± 0.017 %; HFL: 0.045 ± 0.022 %; HFP: 0.033 ± 0.013 %), demonstrating that lipid uptake was not affected by the diet regimen. At 24 h, on the other hand, 13C enrichment of liver lipids decreased in CON, whereas in both high-fat diet groups the 13C enrichment did not change compared to 4 h, indicating a lower turnover of the stored liver lipids. Conclusion: High-fat diet feeding did not alter liver lipid uptake in rats, but resulted in a decreased turnover of the lipids stored in the liver. This research was funded by the Netherlands Consortium for Systems Biology (NCSB) which is part of the Netherlands Genomics Initiative/Netherlands Organisation for Scientific Research

    Seismic scattering and absorption mapping of debris flows, feeding paths, and tectonic units at Mount St. Helens volcano

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    Acknowledgments We thank Edoardo Del Pezzo, Ludovic Margerin, Haruo Sato, Mare Yamamoto, Tatsuhiko Saito, Malcolm Hole, and Seth Moran for the valuable suggestions regarding the methodology and interpretation. Greg Waite provided the P wave velocity model of MSH. An important revision of the methods was done after two blind reviews performed before submission. The suggestions of two anonymous reviewers greatly enhanced our ability of imaging structures, interpreting our results, and testing their reliability. The facilities of the IRIS Data Management System, and specifically the IRIS Data Management Center, were used for access to waveform and metadata required in this study, and provided by the Cascades Volcano Observatory – USGS. Interaction with geologists and geographers part of the Landscape Dynamics Theme of the Scottish Alliance for Geoscience, Environment and Society (SAGES) has been important for the interpretation of the results.Peer reviewedPostprin

    A comparative analysis of the publication behaviour of MSCA fellows

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    MSCA applicants from South and Eastern European countries underperform researchers from North Western Europe before receiving the grant. However, the median difference disappears by the time of the grant and in the period after this. Due to a higher number of outliers (top performers) among the researchers from North Western Europe, the mean impact scores do remain significantly higher

    Semantic and lexical features of words dissimilarly affected by non-fluent, logopenic, and semantic primary progressive aphasia

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    OBJECTIVE: To determine the effect of three psycholinguistic variables-lexical frequency, age of acquisition (AoA), and neighborhood density (ND)-on lexical-semantic processing in individuals with non-fluent (nfvPPA), logopenic (lvPPA), and semantic primary progressive aphasia (svPPA). Identifying the scope and independence of these features can provide valuable information about the organization of words in our mind and brain. METHOD: We administered a lexical decision task-with words carefully selected to permit distinguishing lexical frequency, AoA, and orthographic ND effects-to 41 individuals with PPA (13 nfvPPA, 14 lvPPA, 14 svPPA) and 25 controls. RESULTS: Of the psycholinguistic variables studied, lexical frequency had the largest influence on lexical-semantic processing, but AoA and ND also played an independent role. The results reflect a brain-language relationship with different proportional effects of frequency, AoA, and ND in the PPA variants, in a pattern that is consistent with the organization of the mental lexicon. Individuals with nfvPPA and lvPPA experienced an ND effect consistent with the role of inferior frontal and temporoparietal regions in lexical analysis and word form processing. By contrast, individuals with svPPA experienced an AoA effect consistent with the role of the anterior temporal lobe in semantic processing. CONCLUSIONS: The findings are in line with a hierarchical mental lexicon structure with a conceptual (semantic) and a lexeme (word-form) level, such that a selective deficit at one of these levels of the mental lexicon manifests differently in lexical-semantic processing performance, consistent with the affected language-specific brain region in each PPA variant

    Structured specifications for better verification of heap-manipulating programs

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    Abstract. Conventional specifications typically have a flat structure that is based primarily on the underlying logic. Such specifications lack structures that could have provided better guidance to the verification process. In this work, we propose to add three new structures to a specification framework for separation logic to achieve a more precise and better guided verification for pointer-based programs. The newly introduced structures empower users with more control over the verification process in the following ways: (i) case analysis can be invoked to take advantage of disjointness conditions in the logic. (ii) early, as opposed to late, instantiation can minimise on the use of existential quantification. (iii) formulae that are staged provide better reuse of the verification process. Initial experiments have shown that structured specifications can lead to more precise verification without incurring any performance overhead.

    An in silico Framework of Cartilage Degeneration That Integrates Fibril Reorientation and Degradation Along With Altered Hydration and Fixed Charge Density Loss

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    Injurious mechanical loading of articular cartilage and associated lesions compromise the mechanical and structural integrity of joints and contribute to the onset and progression of cartilage degeneration leading to osteoarthritis (OA). Despite extensive in vitro and in vivo research, it remains unclear how the changes in cartilage composition and structure that occur during cartilage degeneration after injury, interact. Recently, in silico techniques provide a unique integrated platform to investigate the causal mechanisms by which the local mechanical environment of injured cartilage drives cartilage degeneration. Here, we introduce a novel integrated Cartilage Adaptive REorientation Degeneration (CARED) algorithm to predict the interaction between degenerative variations in main cartilage constituents, namely collagen fibril disorganization and degradation, proteoglycan (PG) loss, and change in water content. The algorithm iteratively interacts with a finite element (FE) model of a cartilage explant, with and without variable depth to full-thickness defects. In these FE models, intact and injured explants were subjected to normal (2 MPa unconfined compression in 0.1 s) and injurious mechanical loading (4 MPa unconfined compression in 0.1 s). Depending on the mechanical response of the FE model, the collagen fibril orientation and density, PG and water content were iteratively updated. In the CARED model, fixed charge density (FCD) loss and increased water content were related to decrease in PG content. Our model predictions were consistent with earlier experimental studies. In the intact explant model, minimal degenerative changes were observed under normal loading, while the injurious loading caused a reorientation of collagen fibrils toward the direction perpendicular to the surface, intense collagen degradation at the surface, and intense PG loss in the superficial and middle zones. In the injured explant models, normal loading induced intense collagen degradation, collagen reorientation, and PG depletion both on the surface and around the lesion. Our results confirm that the cartilage lesion depth is a crucial parameter affecting tissue degeneration, even under physiological loading conditions. The results suggest that potential fibril reorientation might prevent or slow down fibril degradation under conditions in which the tissue mechanical homeostasis is perturbed like the presence of defects or injurious loading
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