6,994 research outputs found
Perturbative calculation of quasi-normal modes of Schwarzschild black holes
We discuss a systematic method of analytically calculating the asymptotic
form of quasi-normal frequencies of a four-dimensional Schwarzschild black hole
by expanding around the zeroth-order approximation to the wave equation
proposed by Motl and Neitzke. We obtain an explicit expression for the
first-order correction and arbitrary spin. Our results are in agreement with
the results from WKB and numerical analyses in the case of gravitational waves.Comment: 11 pages; references added and a sign error corrected; to appear in
CQ
Final draft of Pilot Area Conceptual Models and narrative storylines, and including a list of short term policy options
Using the TIDieR checklist to standardize the description of a functional strength training intervention for the upper limb after stroke
Background and Purpose: Published reports of intervention in randomized controlled trials are often poorly described. The Template for Intervention Description and Replication (TIDieR) checklist has been recently developed to improve the reporting of interventions. The aim of this article is to describe a therapy intervention used in the stroke rehabilitation trial, "Clinical Efficacy of Functional Strength Training for Upper Limb Motor Recovery Early After Stroke: Neural Correlates and Prognostic Indicators" (FAST-INdICATE), using TIDieR. Methods: The functional strength training intervention used in the FAST-INdICATE trial was described using TIDieR so that intervention can be replicated by both clinicians, who may implement it in practice, and researchers, who may deliver it in future research. The usefulness of TIDieR in the context of a complex stroke rehabilitation intervention was then discussed. Results and Discussion: The TIDieR checklist provided a systematic way of describing a treatment intervention used in a clinical trial of stroke rehabilitation. Clarification is needed regarding several aspects of the TIDieR checklist, including in which section to report about the development of the intervention in pilot studies, results of feasibility studies; overlap between training and procedures for assessing fidelity; and where to publish supplementary material so that it remains in the public domain. Summary: TIDieR is a systematic way of reporting the intervention delivered in a clinical trial of a complex intervention such as stroke rehabilitation. This approach may also have value for standardizing intervention in clinical practice. Video abstract is available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A131)
Improved algorithms for machine allocation in manufacturing systems
In this paper we present two algorithms for a machine allocation problem occurring in manufacturing systems. For thetwo algorithms presented we prove worst-case performance ratios of 2 and 312, respectively. The machlne allocat~onproblem we consider is a general convex resource allocation problem, which makes the algorithms applicable to a varletyof resource allocation problems. Numerical results are presented for two real-life manufacturing systems.networks;manufacturing;allocation of machines;performance/productivity;queues
Response-related potentials during semantic priming: the effect of a speeded button response task on ERPs
This study examines the influence of a button response task on the event-related potential (ERP) in a semantic priming experiment. Of particular interest is the N400 component. In many semantic priming studies, subjects are asked to respond to a stimulus as fast and accurately as possible by pressing a button. Response time (RT) is recorded in parallel with an electroencephalogram (EEG) for ERP analysis. In this case, the response occurs in the time window used for ERP analysis and response-related components may overlap with stimulus-locked ones such as the N400. This has led to a recommendation against such a design, although the issue has not been explored in depth. Since studies keep being published that disregard this issue, a more detailed examination of influence of response-related potentials on the ERP is needed. Two experiments were performed in which subjects pressed one of two buttons with their dominant hand in response to word-pairs with varying association strength (AS), indicating a personal judgement of association between the two words. In the first experiment, subjects were instructed to respond as fast and accurately as possible. In the second experiment, subjects delayed their button response to enforce a one second interval between the onset of the target word and the button response. Results show that in the first experiment a P3 component and motor-related potentials (MRPs) overlap with the N400 component, which can cause a misinterpretation of the latter. In order to study the N400 component, the button response should be delayed to avoid contamination of the ERP with response-related components
Pan-European backcasting exercise, enriched with regional perspective, and including a list of short-term policy options
This deliverable reports on the results of the third and final pan-European stakeholder meeting and secondly, on the enrichment with a Pilot Area and regional perspective. The main emphasis is on backcasting as a means to arrive at long-term strategies and short-term (policy) actions
Global surface water quality hotspots under climate change and anthropogenic developments
In recent decades, freshwater usage for various sectors (e.g. agriculture, industry, energy and domestic) has more than doubled. A growing global population will place further demands on water supplies, whereas the availability and quality of water resources will be affected by climate change and human impacts. These developments will increase imbalances between fresh water demand and supply in terms of both water quantity and water quality.
Here we discuss a methodology to identify regions of the world where surface water quality is expected to deteriorate under climate change and anthropogenic developments. Our approach integrates global hydrological-water quality modelling, climate and socio-economic scenarios and relations of water quality with physical and socio-economic drivers
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