4,078 research outputs found

    Swath Mapping Data Management Within the National Oceanic and Atmospheric Administration

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    In 1983, the United States proclaimed the establishment of a maritime Exclusive Economic Zone (EEZ) extending beyond the territorial sea to a distance of 200 nautical miles from its coastline. The proclamation reserved for the U.S. the sovereign right to explore for, exploit, conserve, and manage all natural resources within this new 3.4 million square nautical mile territory, an area roughly 1.2 times the total U.S. land mass. In order to help determine the characteristics and resources of the U.S. EEZ, a detailed program was developed to systematically map the entire area using multi-beam swath sounding systems. The program is under the direction of the National Oceanic and Atmospheric Administration (NOAA), United States Department of Commerce. Field operations commenced in early 1984 as two NOAA ships, equipped with advanced bathymetric swath mapping and precision navigation capabilities, began surveying off the coast of central California. Two additional ships have been added since and, to date, 36,000 square nautical miles of bathymetric mapping have been completed, a product of 95,000 lineal nautical miles of swath sounding. With such an enormous amount of data produced by swath mapping systems, the necessity for a comprehensive data management program was recognized early in the project. This paper describes the two-level data management system that has evolved, the lower level utilized aboard NOAA ships that acquire and initially process swath data, and the upper level employed by the Ocean Mapping Section, which is responsible for receiving, verifying, final processing and archiving all bathymetric swath data

    An electrooptical muscle contraction sensor

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    An electrooptical sensor for the detection of muscle contraction is described. Infrared light is injected into the muscle, the backscattering is observed, and the contraction is detected by measuring the change, that occurs during muscle contraction, between the light scattered in the direction parallel and perpendicular to the muscle cells. With respect to electromyography and to optical absorption-based sensors, our device has the advantage of lower invasiveness, of lower sensitivity to electromagnetic noise and to movement artifacts, and of being able to distinguish between isometric and isotonic contractions

    Grundfos: Chlorination of Swimming Pools

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    In this report a model is developed for describing the mixing of chemicals in water systems. We construct a three-variable ODE system describing the concentration of chlorine, bacteria, and organic molecules. We show that a pump strategy is effective in regulating the chlorine concentration

    The Explication Defence of Arguments from Reference

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    In a number of influential papers, Machery, Mallon, Nichols and Stich have presented a powerful critique of so-called arguments from reference, arguments that assume that a particular theory of reference is correct in order to establish a substantive conclusion. The critique is that, due to cross-cultural variation in semantic intuitions supposedly undermining the standard methodology for theorising about reference, the assumption that a theory of reference is correct is unjustified. I argue that the many extant responses to Machery et al.’s critique do little for the proponent of an argument from reference, as they do not show how to justify the problematic assumption. I then argue that it can in principle be justified by an appeal to Carnapian explication. I show how to apply the explication defence to arguments from reference given by Andreasen (for the biological reality of race) and by Churchland (against the existence of beliefs and desires)

    Do patients with schizophrenia exhibit aberrant salience?

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    BACKGROUND: It has been suggested that some psychotic symptoms reflect ‘aberrant salience’, related to dysfunctional reward learning. To test this hypothesis we investigated whether patients with schizophrenia showed impaired learning of task-relevant stimulusreinforcement associations in the presence of distracting task-irrelevant cues. METHODS: We tested 20 medicated patients with schizophrenia and 17 controls on a reaction time game, the Salience Attribution Test. In this game, participants made a speeded response to earn money in the presence of conditioned stimuli (CSs). Each CS comprised two visual dimensions, colour and form. Probability of reinforcement varied over one of these dimensions (task-relevant), but not the other (task-irrelevant). Measures of adaptive and aberrant motivational salience were calculated on the basis of latency and subjective reinforcement probability rating differences over the task-relevant and task-irrelevant dimensions respectively. RESULTS: Participants rated reinforcement significantly more likely and responded significantly faster on high-probability reinforced relative to lowprobability reinforced trials, representing adaptive motivational salience. Patients exhibited reduced adaptive salience relative to controls, but the two groups did not differ in terms of aberrant salience. Patients with delusions exhibited significantly greater aberrant salience than those without delusions, and aberrant salience also correlated with negative symptoms. In the controls, aberrant salience correlated significantly with ‘introvertive anhedonia’ schizotypy. CONCLUSIONS: These data support the hypothesis that aberrant salience is related to the presence of delusions in medicated patients with schizophrenia, but are also suggestive of a link with negative symptoms. The relationship between aberrant salience and psychotic symptoms warrants further investigation in unmedicated patients
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