1,518 research outputs found

    The knowledge argument

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    Frank Jackson’s knowledge argument is a very influential piece of reasoning that seeks to show that colour experiences constitute an insoluble problem for science. This argument is based on a thought experiment concerning Mary. She is a vision scientist who has complete scientific knowledge of colours and colour vision but has never had colour experiences. According to Jackson, upon seeing coloured objects, Mary acquires new knowledge that escapes her complete scientific knowledge. He concludes that there are facts concerning colour experiences that scientific knowledge can neither describe nor explain. Specifically, these facts involve the occurrence of certain non-physical properties of experiences that he calls qualia. The present research considers whether a plausible formulation of the hypothesis that science can accommodate colour experiences is threatened by a version of the knowledge argument. The specific formulation of this problem has two motivations. Firstly, before investigating whether the knowledge argument raises a problem for the claim that science can account for colour experiences, we need a plausible formulation of this claim. I argue that the idea that science can accommodate colour experiences can be formulated as the modest reductionism hypothesis. Roughly speaking, this is the hypothesis that a science that can be explanatory interfaced with current physics of ordinary matter can account for conscious experiences. Secondly, an unintelligible premise figures in Jackson’s version the knowledge argument. Namely, it is assumed that Mary possesses a complete (future or possible) scientific knowledge. Nevertheless, the type of strategy involved in Jackson’s argument can be used to target modest reductionism. By considering contemporary psychophysics and neuroscience, I characterise Mary’s scientific knowledge. First, this characterisation is intelligible. In fact, it is elaborated on the basis of descriptions and explanations of colour experiences involved in current physics and neuroscience. Second, a supporter of modest reductionism can assume that the scientific knowledge ascribed to Mary might account for colour experiences. The main conclusion of the present research is that our version of the knowledge argument fails to threaten the modest reductionism hypothesis. In fact, I endorse what can be called the “two ways of thinking” reply to the knowledge argument. According to this response, the knowledge argument shows that there are different ways of thinking about colour experiences. One way of thinking is provided by scientific knowledge. The other way of thinking is provided by our ordinary conception of colour experiences. However, the existence of these two ways of thinking does not imply the existence of facts and properties that escape scientific knowledge. It might be the case that the ordinary way of thinking about colour experience concerns facts and properties described and explained by science. The principal conclusion of the research results from two investigations. The first line of research aims to reveal and evaluate the implicit assumptions that figure in the knowledge argument. The main body of the research is dedicated to this task. The principal result of this investigation is that the knowledge argument must rely on an account of introspective knowledge of colour experiences. I argue that an inferential model of introspection provides such account. On this model, Mary’s capacity to hold beliefs about her colour experiences when she sees coloured objects requires her mastery of colour concepts. The second main investigation seeks to justify the two ways of thinking strategy. As many opponents and supporters have recently started to realise, this strategy might be charged with being ad hoc. I offer a distinctive justification of this reply to the knowledge argument. Assuming the account of introspection mentioned above, the existence of visual recognitional colour concepts might justify this strategy. A person possesses these concepts when she is able to determine the colours of objects simply by having visual experiences.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Spongionella Secondary Metabolites, Promising Modulators of Immune Response through CD147 Receptor Modulation

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    The modulation of the immune system can have multiple applications such as cancer treatment, and a wide type of processes involving inflammation where the potent chemotactic agent cyclophilin A (Cyp A) is implicated. The Porifera phylum, in which Spongionella is encompassed, is the main producer of marine bioactive compounds. Four secondary metabolites obtained from Spongionella (Gracilin H, A, L, and Tetrahydroaplysulphurin-1) were described to hit Cyp A and to block the release of inflammation mediators. Based on these results, some role of Spongionella compounds on other steps of the signaling pathway mediated by this chemotactic agent can be hypothesized. In the present paper, we studied the effect of these four compounds on the surface membrane CD147 receptor expression, on the extracellular levels of Cyp A and on the ability to migrate of concanavalin (Con A)-activated T lymphocytes. Similar to a well-known immunosuppressive agent cyclosporine A (CsA), Gracilin H, A, L, and tetrahydroaplysulphurin-1 were able to reduce the CD147 membrane expression and to block the release of Cyp A to the medium. Besides, by using Cyp A as chemotactic agent, T cell migration was inhibited when cells were previously incubated with Gracilin A and Gracilin L. These positive results lead us to test the in vivo effect of Gracilin H and L in a mouse ear delayed hypersensitive reaction. Thus, both compounds efficiently reduce the ear swelling as well as the inflammatory cell infiltration. These results provide more evidences for their potential therapeutic application in immune-related diseases of Spongionella compound

    The Role of Canyons in Strata Formation

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    This paper provides a spatial and temporal multi-scale approach of European submarine canyons. We fi rst present the long-term geologic view of European margins as related to controls on submarine canyon development. Then we discuss the extent to which submarine canyon systems resemble river systems because both essentially form drainage networks. Finally, we deal with the hortest-term, highestresolution scale to get a fl avor of the current functioning and health of modern submarine canyons in the northwestern Mediterranean Sea. Submarine canyons are unique features of the seafl oor whose existence was known by European fi shermen centuries ago, especially for those canyons that have their heads at short distance from shoreline. Popular names given to specifi c canyons in the different languages spoken in European coastal communities refer to the concepts of a"deep" or"trench." In the old times it was also common thinking that submarine canyons where so deep that nobody could measure their depth or even that they had no bottom. Submarine canyons are just one of the seven different types of seafl oor valleys identifi ed by Shepard (1973) in his pioneering morphogenetic classifi cation. Shepard (1973) defined submarine canyons as"steep-walled, sinuous valleys, with V-shaped cross sections, and relief comparable even to the largest of land canyons; tributaries are found in most of the canyons and rock outcrops abound on their walls." Canyons are features typical of continental slopes with their upper reaches and heads cut into the continental shelf

    Influence of feedstock demineralization on the chemical composition of pyrolysis vapours derived from sugarcane residues in py-GC/MS

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    Sugarcane bagasse (SCB) and trash (SCT) are prospective feedstock materials for fast pyrolysis systems. However, their relatively high inorganic content, especially alkali and alkaline earth metals (AAEMs), affects the quality of the produced bio-oil. In order to overcome this problem, various chemical pretreatment methods have been developed. This study aims to evaluate the effect of demineralization of SCB and SCT on the chemical composition of the bio-oil, viz. by applying micro-pyrolysis (py-GC/MS). Both biomass types were leached with demineralized water, HCl, H2SO4 and citric acid solutions at different temperatures and leaching times. The results indicate that leaching with either inorganic or organic acids, causes the yields of levoglucosan in the pyrolysis vapours to increase. This is explained by the mitigation of undesirable degradation reactions of cellulose and cellulose intermediates in the presence of catalytically active AAEMs, the latter being partially removed in the leaching process. The limited variations in yield of phenolic compounds upon different pretreatments demonstrated the stability of the lignin irrespective any leaching pretreatment. The composition of pyrolysis vapours derived from citric acid-treated biomass is hardly influenced by any changes in demineralization conditions

    Quantifying local rainfall dynamics and uncertain boundary conditions into a nested regional-local flood modeling system

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    [Abstract:] Inflow discharge and outflow stage estimates for hydraulic flood models are generally derived from river gauge data. Uncertainties in the measured inflow data and the neglect of rainfall-runoff contributions to the modeled domain downstream of the gauging locations can have a significant impact on these estimated “whole reach” inflows and consequently on flood predictions. In this study, a method to incorporate rating curve uncertainty and local rainfall-runoff dynamics into the predictions of a reach-scale flood model is proposed. The methodology is applied to the July 2007 floods of the River Severn in UK. Discharge uncertainty bounds are generated applying a nonparametric local weighted regression approach to stage-discharge measurements for two gauging stations. Measured rainfall downstream from these locations is used as input to a series of subcatchment regional hydrological model to quantify additional local inflows along the main channel. A regional simplified-physics hydraulic model is then applied to combine these contributions and generate an ensemble of discharge and water elevation time series at the boundaries of a local-scale high complexity hydraulic model. Finally, the effect of these rainfall dynamics and uncertain boundary conditions are evaluated on the local-scale model. Accurate prediction of the flood peak was obtained with the proposed method, which was only possible by resolving the additional complexity of the extreme rainfall contributions over the modeled area. The findings highlight the importance of estimating boundary condition uncertainty and local rainfall contributions for accurate prediction of river flows and inundation at regional scales.María Bermúdez gratefully acknowledges financial support from the Spanish Regional Government of Galicia (postdoctoral grant reference ED481B 2014/156-0). Gemma Coxon was supported by NERC MaRIUS: Managing the Risks, Impacts and Uncertainties of droughts and water Scarcity, grant NE/L010399/1. Jim Freer and Paul Bates by NERC Susceptibility of catchments to INTense RAinfall and flooding, grant NE/K00882X/1. A free version of the model LISFLOOD-FP is available for download at www.bristol.ac.uk/geography/research/hydrology/models/lisflood/. A free version of the model Iber is available for download at www.iberaula.es. The river cross-section data, the LiDAR digital elevation model and the gauging station rainfall, stage, flow and rating curve data of the presented case study are freely available from the Environment Agency ([email protected])Xunta de Galicia; ED481B 2014/156-0Inglaterra. University of Bristol; NE/L010399/1Inglaterra. University of Bristol; NE/K00882X/

    SMAD3 rs17228212 Gene Polymorphism Is Associated with Reduced Risk to Cerebrovascular Accidents and Subclinical Atherosclerosis in Anti-CCP Negative Spanish Rheumatoid Arthritis Patients

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    Rheumatoid arthritis (RA) is a complex polygenic inflammatory disease associated with accelerated atherosclerosis and increased risk of cardiovascular (CV) disease. Previous genome-wide association studies have described SMAD3 rs17228212 polymorphism as an important signal associated with CV events. The aim of the present study was to evaluate for the first time the relationship between this gene polymorphism and the susceptibility to CV manifestations and its potential association with the presence of subclinical atherosclerosis assessed by the evaluation of carotid intima-media thickness (cIMT) in patients with RA
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