40 research outputs found
Simulation of static and random errors on Grover's search algorithm implemented in a Ising nuclear spin chain quantum computer with few qubits
We consider Grover's search algorithm on a model quantum computer implemented
on a chain of four or five nuclear spins with first and second neighbour Ising
interactions. Noise is introduced into the system in terms of random
fluctuations of the external fields. By averaging over many repetitions of the
algorithm, the output state becomes effectively a mixed state. We study its
overlap with the nominal output state of the algorithm, which is called
fidelity. We find either an exponential or a Gaussian decay for the fidelity as
a function of the strength of the noise, depending on the type of noise (static
or random) and whether error supression is applied (the 2pi k-method) or not.Comment: 18 pages, 8 figures, extensive revision with new figure
Toxic effects of phenothiazines on the eye
Publications about the retinotoxic action of phenothiazine derivatives led the author to undertake an ophthalmological investigation in two psychiatric hospitals in The Netherlands.
The pharmacological actions of phenothiazine preparations are listed and a survey of the phenothiazine derivatives which are at present in use is given. Some retinotoxic substances are discussed and a survey is given of the literature on the ocular complications of phenothiazine therapy.
The eyes of 561 patients were examined. of whom 541 are included in this study. 343 of these patients(63.4 %) were found to have retinopathy. The correlation between the retinopathy and the total dose of phenothiazine preparations taken. and between the retinopathy and the duration of treatment. was highly significant. The correlation between the retinopathy and the average daily dose taken was significant.
The retinopathy was associated with a reduced standing potential of the eye. as determined by electro-oculography. It was possibly responsible for diminished visual acuity in some cases, and for an abnormally large proportion of protans in the group of patients with colour defects.
It was not possible to ascribe a more severe retinotoxic action to one or more specific phenothiazine derivatives than to others.
In the author's opinion regular examination of the eyes of patients who are being treated with phenothiazine preparations in high dosage and for for a long period of time is indicated
Stepping out of history:Mindfulness improves insight problem solving
Insight problem solving is hindered by automated verbal-conceptual processes. Because mindfulness meditation training aims at "nonconceptual awareness" which involves a reduced influence of habitual verbal-conceptual processes on the interpretation of ongoing experience, mindfulness may facilitate insight problem solving. This hypothesis was examined across two studies (total N = 157). Participants in both studies completed a measure of trait mindfulness and a series of insight and noninsight problems. Further, participants in Study 2 completed measures of positive affect and a mindfulness or control training. The results indicated that (a) trait mindfulness predicts better insight but not noninsight problem solving (both studies), (b) this relation is maintained when controlling for positive affect (Study 2), (c) mindfulness training improves insight but not noninsight problem solving (Study 2) and (d) this improvement is partially mediated by state mindfulness (Study 2). These findings are the first to document a direct relation between mindfulness and creativity. (C) 2012 Elsevier Inc. All rights reserved
Predicting dyscontrolled drinking with implicit and explicit measures of alcohol motivation
Background A defining feature of alcohol addiction is dyscontrol – drinking despite intentions to restrain use. Given that dyscontrolled drinking involves an automatic (nonvolitional) element and that implicit measures are designed to assess automatic processes, it follows that implicit measures may be particularly useful for predicting dyscontrolled alcohol use. Although there is accumulating evidence for the benefit of using implicit measures to predict nonvolitional behaviors, relatively little research has examined such predictive validity for alcohol dyscontrol. The current study was designed to examine whether an implicit measure of alcohol attitude would predict variance of dyscontrol above that explained by typical drinking behavior and an explicit measure of alcohol attitude. Methods A sample of 62 undergraduate students completed implicit and explicit measures of alcohol-positive (relative to alcohol-negative) valence associations and retrospective self-report measures of typical drinking behavior and difficulty in controlling alcohol consumption. Results Both the implicit and explicit measures predicted alcohol dyscontrol. The implicit measure continued to predict dyscontrol when controlling for the explicit measure and typical drinking behavior. Conclusions These findings indicate that assessing the automaticity of alcohol-positive associations may be beneficial for predicting clinically relevant behaviors such as post-treatment outcome
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Integration and testing of hot desulfurization and entrained flow gasification for power generation systems
To help achieve the goal of clean, low cost power generation from coal, Texaco submitted an unsolicited proposal in July 1986 to develop and demonstrate the integration of high temperature desulfurization with the Texaco Coal Gasification Process (TCGP). The main goals of the proposed program were: Develop and demonstrate in-situ desulfurization of synthesis gas in an entrained flow gasifier using both air and oxygen gasification. Develop and demonstrate a high efficiency integrated system on a process development unit (PDU) scale which would include coal preparation, gasification, sulfur removal, particle and trace element removal and a gas turbine. In addition, secondary goals were proposed which would help further major research in which DOE/METC was already involved. These were: Test advanced instruments developed by METC for coal conversion processes. Screen alternative high temperature sulfur removal sorbents that could be used external to the gasifier. Development of these sorbents would provide a backup to the in-situ desulfurization approach. Accomplishments to date are presented
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Integration and testing of hot desulfurization and entrained-flow gasification for power generation systems. Phase 2, Process optimization: Volume 1, Program summary and PDU operations
This second Topical Report describes the work that was completed between January 1, 1989 and December 31, 1990 in a Cooperative Agreement between Texaco and the US Department of Energy that began on September 30, 1987. During the period that is covered in this report, the development and optimization of in-situ and external desulfurization processes were pursued. The research effort included bench scale testing, PDU scoping tests, process economic studies and advanced instrument testing. Two bench scale studies were performed at the Research Triangle Institute with zinc titanate sorbent to obtain data on its cycle life, sulfur capacity, durability and the effect of chlorides. These studies quantify sulfur capture during simulated air and oxygen-blown gasification for two zinc titanate formulations. Eight PDU runs for a total of 20 days of operation were conducted to evaluate the performance of candidate sorbents for both in-situ and external desulfurization. A total of 47 tests were completed with oxygen and air-blown gasification. Candidate sorbents included iron oxide for in-situ desulfurization and calcium based and mixed metal oxides for external desulfurization. Gasifier performance and sorbent sulfur capture are compared for both air-blown and oxygen-blown operation