44 research outputs found
Connectivity of consecutive-d digraphs
AbstractThe concept of consecutive-d digraph is proposed by Du, Hsu and Hwang. It generalizes the class of de Bruijin digraphs, the class of Imase-Itoh digraphs and the class of generalized de Bruijin graphs. We modify consecutive-d digraphs by connecting nodes with a loop into a circuit and deleting all loops. The result in this paper shows that the link-connectivity or the connectivity of modified consecutive-d digraphs get better
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Development of a database management system for Coal Combustion By-Products (CCBs)
Coal combustion by-products (CCBs) are produced in high volumes worldwide. Utilization of these materials is economically and environmentally advantageous and is expected to increase as disposal costs increase. The American Coal Ash Association (ACAA) is developing a database to contain characterization and utilization information on CCBs. This database will provide information for use by managers, marketers, operations personnel, and researchers that will aid in their decision making and long-term planning for issues related to CCBs. The comprehensive nature of the database and the interactive user application will enable ACAA members to efficiently and economically access a wealth of data on CCBs and will promote the technically sound, environmentally safe, and commercially competitive use of CCBs
A systematic review of techniques and effects of self-help interventions for tinnitus: application of taxonomies from health psychology
Objective: Self-help interventions are followed by people independently with minimal or no therapist contact. This review aims to assess the effectiveness of self-help interventions for adults with chronic tinnitus and systematically identify the self-help techniques used. Design: Systematic review and application of health psychology taxonomies. Electronic database searches were conducted, supplemented by citation searching and hand-searching of key journals. Prospective controlled trials, which used measures of tinnitus distress, functional management, anxiety, depression, and quality of life, were included. Michie et al’s behaviour change techniques (BCTs) taxonomy and Taylor et al’s PRISMS taxonomy of self-management components were applied to describe interventions. Study sample: Five studies were included, providing low-to-moderate levels of evidence. Results: Randomized controlled trial studies were too few and heterogeneous for meta-analysis to be performed. Studies comparing self-help interventions to therapist-guided interventions and assessing non tinnitus-specific psychosocial outcomes and functional management were lacking. Fifteen BCTs and eight self-management components were identified across interventions. Conclusions: A lack of high-quality and homogeneous studies meant that confident conclusions could not be drawn regarding the efficacy of self-help interventions for tinnitus. Better reporting and categorization of intervention techniques is needed for replication in research and practice and to facilitate understanding of intervention mechanisms
COVID-19: Rapid antigen detection for SARS-CoV-2 by lateral flow assay: A national systematic evaluation of sensitivity and specificity for mass-testing
Background
Lateral flow device (LFD) viral antigen immunoassays have been developed around the world as diagnostic tests for SARS-CoV-2 infection. They have been proposed to deliver an infrastructure-light, cost-economical solution giving results within half an hour.
Methods
LFDs were initially reviewed by a Department of Health and Social Care team, part of the UK government, from which 64 were selected for further evaluation from 1st August to 15th December 2020. Standardised laboratory evaluations, and for those that met the published criteria, field testing in the Falcon-C19 research study and UK pilots were performed (UK COVID-19 testing centres, hospital, schools, armed forces).
Findings
4/64 LFDs so far have desirable performance characteristics (orient Gene, Deepblue, Abbott and Innova SARS-CoV-2 Antigen Rapid Qualitative Test). All these LFDs have a viral antigen detection of >90% at 100,000 RNA copies/ml. 8951 Innova LFD tests were performed with a kit failure rate of 5.6% (502/8951, 95% CI: 5.1–6.1), false positive rate of 0.32% (22/6954, 95% CI: 0.20–0.48). Viral antigen detection/sensitivity across the sampling cohort when performed by laboratory scientists was 78.8% (156/198, 95% CI 72.4–84.3).
Interpretation
Our results suggest LFDs have promising performance characteristics for mass population testing and can be used to identify infectious positive individuals. The Innova LFD shows good viral antigen detection/sensitivity with excellent specificity, although kit failure rates and the impact of training are potential issues. These results support the expanded evaluation of LFDs, and assessment of greater access to testing on COVID-19 transmission.
Funding
Department of Health and Social Care. University of Oxford. Public Health England Porton Down, Manchester University NHS Foundation Trust, National Institute of Health Research
Characterization of transgenic mouse models targeting neuromodulatory systems reveals organizational principles of the dorsal raphe
The dorsal raphe (DR) is a heterogeneous nucleus containing dopamine (DA), serotonin (5HT), γ-aminobutyric acid (GABA) and glutamate neurons. Consequently, investigations of DR circuitry require Cre-driver lines that restrict transgene expression to precisely defined cell populations. Here, we present a systematic evaluation of mouse lines targeting neuromodulatory cells in the DR. We find substantial differences in specificity between lines targeting DA neurons, and in penetrance between lines targeting 5HT neurons. Using these tools to map DR circuits, we show that populations of neurochemically distinct DR neurons are arranged in a stereotyped topographical pattern, send divergent projections to amygdala subnuclei, and differ in their presynaptic inputs. Importantly, targeting DR DA neurons using different mouse lines yielded both structural and functional differences in the neural circuits accessed. These results provide a refined model of DR organization and support a comparative, case-by-case evaluation of the suitability of transgenic tools for any experimental application
Optimal Hedging with a Subjective View: An Empirical Bayesian Approach
The standard optimal hedging model has been the preferred theoretical model of normative hedging behavior. In empirical applications, the model is often implemented with the parameter certainty equivalent (PCE) procedure. However, the PCE procedure completely ignores parameter estimation risk and subjective views. We develop an “empirical” Bayesian optimal hedging model that not only effectively accommodates parameter estimation risk, but also provides hedgers with a theoretically intuitive yet quantitatively rigorous framework to blend their subjective views and a “marketwide” or “firmwide” consensus in determining optimal hedging positions (ratios). Copyright 2005, Oxford University Press.