scholarly journals BAYESIAN GROUP TESTING WITH DILUTION EFFECTS

2021 ◽  
Author(s):  
Curtis Tatsuoka ◽  
Weicong Chen
Keyword(s):  
Selection Rule ◽  
Group Testing ◽  
Binary Outcomes ◽  
Repeated Testing ◽  
Web Based ◽  
General Test ◽  
Wide Scale ◽  
Health Need ◽  
Dilution Effects ◽  
Strong Dilution

AbstractA Bayesian framework for group testing under dilution effects is introduced. This work has particular relevance given the pressing public health need to enhance testing capacity for COVID-19, and the need for wide-scale and repeated testing for surveillance. The proposed Bayesian approach allows for dilution effects in group testing and for general test response distributions beyond just binary outcomes. It is shown that even with strong dilution effects, an intuitive and simple-to-implement group testing selection rule, referred to as the Bayesian halving algorithm, has attractive optimal properties. A web-based calculator is introduced to assist and guide decisions on when and how to pool under various conditions.

A Test Sheet Optimization Approach to Supporting Web-based Learning Diagnosis Using Group Testing Methods

2017 ◽  
Vol 7 (4) ◽  
pp. 1-23
Author(s):  
Chu-Fu Wang ◽  
Chih-Lung Lin ◽  
Gwo-Jen Hwang ◽  
Sheng-Pin Kung ◽  
Shin-Feng Chen
Keyword(s):  
Test Item ◽  
Group Testing ◽  
Diagnostic System ◽  
Point Of View ◽  
Optimization Approach ◽  
Exposure Rate ◽  
Web Based ◽  
Item Exposure ◽  
Test Items ◽  
Doubling Method

Assessment can help teachers to examine the effectiveness of teaching and to diagnose the unfamiliar basic concepts (or attributes) of students within the testing scope. A web-based adaptive testing and diagnostic system can achieve the above objective efficiently and correctly. From a diagnostic point of view, the major concerns are to diagnose whether or not an examinee has learned each basic concept well in the testing scope, while also limiting the number of test items used (the testing length) to as few as possible, which will be directly related to the patience of the examinee. In this paper, we consider a test item selecting optimization diagnostic problem to reveal the mastery profile of an examinee (that is, to diagnose each basic concept's learning status (well learned/unfamiliar) in the testing scope) with a short testing length and a limited test item exposure rate. This paper uses the techniques of Group Testing theory for the design of our test item selecting algorithm. Two test item selecting strategies, the bisecting method and the doubling method, are proposed. The effectiveness of the proposed methods was evaluated by experimental simulations. The results show that both of the proposed algorithms use fewer test items and a limited test item exposure rate compared to the conventional methods.

scholarly journals Assessment of Specimen Pooling to Conserve SARS CoV-2 Testing Resources

2020 ◽  
Vol 153 (6) ◽  
pp. 715-718 ◽  
Author(s):  
Baha Abdalhamid ◽  
Christopher R Bilder ◽  
Emily L McCutchen ◽  
Steven H Hinrichs ◽  
Scott A Koepsell ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Group Testing ◽  
Viral Rna ◽  
Optimal Parameters ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Web Based ◽  
Negative Patient ◽  
Cycle Threshold ◽  
Unselected Group

Abstract Objectives To establish the optimal parameters for group testing of pooled specimens for the detection of SARS-CoV-2. Methods The most efficient pool size was determined to be five specimens using a web-based application. From this analysis, 25 experimental pools were created using 50 µL from one SARS-CoV-2 positive nasopharyngeal specimen mixed with 4 negative patient specimens (50 µL each) for a total volume of 250 µL. Viral RNA was subsequently extracted from each pool and tested using the CDC SARS-CoV-2 RT-PCR assay. Positive pools were consequently split into individual specimens and tested by extraction and PCR. This method was also tested on an unselected group of 60 nasopharyngeal specimens grouped into 12 pools. Results All 25 pools were positive with cycle threshold (Ct) values within 0 and 5.03 Ct of the original individual specimens. The analysis of 60 specimens determined that 2 pools were positive followed by identification of 2 individual specimens among the 60 tested. This testing was accomplished while using 22 extractions/PCR tests, a savings of 38 reactions. Conclusions When the incidence rate of SARS-CoV-2 infection is 10% or less, group testing will result in the saving of reagents and personnel time with an overall increase in testing capability of at least 69%.

A general regression framework for group testing data, which incorporates pool dilution effects

2015 ◽  
Vol 34 (27) ◽  
pp. 3606-3621 ◽  
Author(s):  
Dewei Wang ◽  
Christopher S. McMahan ◽  
Colin M. Gallagher
Keyword(s):  
Group Testing ◽  
Regression Framework ◽  
Testing Data ◽  
Dilution Effects ◽  
General Regression

scholarly journals Regression models for group testing data with pool dilution effects

Biostatistics ◽  
2012 ◽  
Vol 14 (2) ◽  
pp. 284-298 ◽  
Author(s):  
C. S. McMahan ◽  
J. M. Tebbs ◽  
C. R. Bilder
Keyword(s):  
Regression Models ◽  
Group Testing ◽  
Testing Data ◽  
Dilution Effects

scholarly journals A RE-AIM evaluation in early adopters to iteratively improve the online BeUpstanding™ program supporting workers to sit less and move more

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Genevieve N. Healy ◽  
Elisabeth A. H. Winkler ◽  
Ana D. Goode
Keyword(s):  
Comprehensive Evaluation ◽  
Work Team ◽  
Web Based ◽  
Early Adopters ◽  
Iterative Development ◽  
Level Data ◽  
National Implementation ◽  
Integrated Delivery ◽  
Wide Scale ◽  
Evaluation Platform

Abstract Background The web-based BeUpstanding program supports desk workers to sit less and move more. Successfully translated from a research-delivered intervention, BeUpstanding has gone through iterative development and evaluation phases in preparation for wide-scale implementation. In the third planned “early-adopters” phase (01/09/2017–11/06/2019), the program was made freely-available online. An integrated delivery and evaluation platform was also developed to enable workplace champions to run and evaluate the intervention within their work team independent of researcher support. Using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) framework, this study reports on the extent to which the program and processes were “fit-for-purpose” for a national implementation trial across the indicators of uptake (reach and adoption), implementation and engagement, and effectiveness for behaviour change. Methods Data were collected via the online surveys embedded in the program and through program access analytics. Descriptive data (with linearized variance for the clustered staff-level data) and results from mixed models (repeated data and clustering for pre-post changes) are reported. Results Despite purposeful limited promotion, uptake was good, with 182 Australian users initially registering (208 total) and 135 (from 113 organisations) then completing the sign-up process. Recruitment reached users across Australia and in 16 of 19 Australian industries. Implementation was inconsistent and limited, with signed-up users completing 0 to 14 of the program’s 14 steps and only 7 (5.2%) completing all seven core steps. Many champions (n = 69, 51.1%) had low engagement (1 day toolkit usage) and few (n = 30, 22%) were highly engaged (> 1 day toolkit usage and surveyed staff). Although only 18 users (7 organisations) performed the pre- and post-program staff evaluations (337 and 167 staff, respectively), pre-post changes showed the program effectively reduced workplace sitting by − 9.0% (95% CI -12.0, − 5.9%). Discussion The program had uptake across industries and across Australia, but implementation and engagement varied widely. Few workplaces completed the evaluation components. In those that did, the program was effective for the primary outcome (workplace sitting). Conducting a planned early adopters phase and a comprehensive evaluation according to RE-AIM helped highlight necessary program improvements to make it more suitable for wide-scale implementation and evaluation. Trial registration Australian and New Zealand Clinic Trials Registry ACTRN12617000682347. Date registered: 12/05/2017.

scholarly journals Carrier and dilution effects of CO 2 on thoron emissions from a zeolitized tuff exposed to subvolcanic temperatures

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Silvio Mollo ◽  
Piergiorgio Moschini ◽  
Gianfranco Galli ◽  
Paola Tuccimei ◽  
Carlo Lucchetti ◽  
...  
Keyword(s):  
Noble Gas ◽  
Temperature Gradients ◽  
Water Molecules ◽  
Hydroxyl Groups ◽  
Flux Rate ◽  
Advective Transport ◽  
Structural Modifications ◽  
Intermolecular Proton Transfer ◽  
Dilution Effects ◽  
Strong Dilution

Radon ( 222 Rn) and thoron ( 220 Rn) are two isotopes belonging to the noble gas radon ( sensu lato ) that is frequently employed for the geochemical surveillance of active volcanoes. Temperature gradients operating at subvolcanic conditions may induce chemical and structural modifications in rock-forming minerals and their related 222 Rn– 220 Rn emissions. Additionally, CO 2 fluxes may also contribute enormously to the transport of radionuclides through the microcracks and pores of subvolcanic rocks. In view of these articulated phenomena, we have experimentally quantified the changes of 220 Rn signal caused by dehydration of a zeolitized tuff exposed to variable CO 2 fluxes. Results indicate that, at low CO 2 fluxes, water molecules and hydroxyl groups adsorbed on the glassy surface of macro- and micropores are physically removed by an intermolecular proton transfer mechanism, leading to an increase of the 220 Rn signal. By contrast, at high CO 2 fluxes, 220 Rn emissions dramatically decrease because of the strong dilution capacity of CO 2 that overprints the advective effect of carrier fluids. We conclude that the sign and magnitude of radon ( sensu lato ) changes observed in volcanic settings depend on the flux rate of carrier fluids and the rival effects between advective transport and radionuclide dilution.

scholarly journals MethylDetectR: a software for methylation-based health profiling

2021 ◽  
Vol 5 ◽  
pp. 283
Author(s):  
Robert F. Hillary ◽  
Riccardo E. Marioni
Keyword(s):  
Dna Methylation ◽  
Disease Risk ◽  
Reference Sample ◽  
Unmet Need ◽  
Density Lipoprotein ◽  
Binary Outcomes ◽  
Web Based ◽  
Individual Level ◽  
Reversible Addition ◽  
Important Health

DNA methylation is an important biological process that involves the reversible addition of chemical tags called methyl groups to DNA and affects whether genes are active or inactive. Individual methylation profiles are determined by both genetic and environmental influences. Inter-individual variation in DNA methylation profiles can be exploited to estimate or predict a wide variety of human characteristics and disease risk profiles. Indeed, a number of methylation-based predictors of human traits have been developed and linked to important health outcomes. However, there is an unmet need to communicate the applicability and limitations of state-of-the-art methylation-based predictors to the wider community. To address this need, we have created a secure, web-based interactive platform called ‘MethylDetectR’ which automates the calculation of estimated values or scores for a variety of human traits using blood methylation data. These traits include age, lifestyle traits and high-density lipoprotein cholesterol. Methylation-based predictors often return scores on arbitrary scales. To provide meaning to these scores, users can interactively view how estimated trait scores for a given individual compare against other individuals in the sample. Users can optionally upload binary phenotypes and investigate how estimated traits vary according to case vs. control status for these phenotypes. Users can also view how different methylation-based predictors correlate with one another, and with phenotypic values for corresponding traits in a large reference sample (n = 4,450; Generation Scotland). The ‘MethylDetectR’ platform allows for the fast and secure calculation of DNA methylation-derived estimates for several human traits. This platform also helps to show the correlations between methylation-based scores and corresponding traits at the level of a sample, report estimated health profiles at an individual level, demonstrate how scores relate to important binary outcomes of interest and highlight the current limitations of molecular health predictors.

scholarly journals Group Testing for SARS-CoV-2 Allows for Up to 10-Fold Efficiency Increase Across Realistic Scenarios and Testing Strategies

2021 ◽  
Vol 9 ◽  
Author(s):  
Claudio M. Verdun ◽  
Tim Fuchs ◽  
Pavol Harar ◽  
Dennis Elbrächter ◽  
David S. Fischer ◽  
...  
Keyword(s):  
Infection Rate ◽  
Web Application ◽  
Diagnostic Testing ◽  
Group Testing ◽  
Population Heterogeneity ◽  
Testing Procedures ◽  
Testing Strategies ◽  
Specificity And Sensitivity ◽  
Novel Coronavirus ◽  
Dilution Effects

Background: Due to the ongoing COVID-19 pandemic, demand for diagnostic testing has increased drastically, resulting in shortages of necessary materials to conduct the tests and overwhelming the capacity of testing laboratories. The supply scarcity and capacity limits affect test administration: priority must be given to hospitalized patients and symptomatic individuals, which can prevent the identification of asymptomatic and presymptomatic individuals and hence effective tracking and tracing policies. We describe optimized group testing strategies applicable to SARS-CoV-2 tests in scenarios tailored to the current COVID-19 pandemic and assess significant gains compared to individual testing.Methods: We account for biochemically realistic scenarios in the context of dilution effects on SARS-CoV-2 samples and consider evidence on specificity and sensitivity of PCR-based tests for the novel coronavirus. Because of the current uncertainty and the temporal and spatial changes in the prevalence regime, we provide analysis for several realistic scenarios and propose fast and reliable strategies for massive testing procedures.Key Findings: We find significant efficiency gaps between different group testing strategies in realistic scenarios for SARS-CoV-2 testing, highlighting the need for an informed decision of the pooling protocol depending on estimated prevalence, target specificity, and high- vs. low-risk population. For example, using one of the presented methods, all 1.47 million inhabitants of Munich, Germany, could be tested using only around 141 thousand tests if the infection rate is below 0.4% is assumed. Using 1 million tests, the 6.69 million inhabitants from the city of Rio de Janeiro, Brazil, could be tested as long as the infection rate does not exceed 1%. Moreover, we provide an interactive web application, available at www.grouptexting.com, for visualizing the different strategies and designing pooling schemes according to specific prevalence scenarios and test configurations.Interpretation: Altogether, this work may help provide a basis for an efficient upscaling of current testing procedures, which takes the population heterogeneity into account and is fine-grained towards the desired study populations, e.g., mild/asymptomatic individuals vs. symptomatic ones but also mixtures thereof.Funding: German Science Foundation (DFG), German Federal Ministry of Education and Research (BMBF), Chan Zuckerberg Initiative DAF, and Austrian Science Fund (FWF).

scholarly journals Development of a Common Format of Questionnaire Tests for a Web-based Platform of Population and Experimental Psychological Research

2018 ◽  
Vol 18 ◽  
pp. 04004
Author(s):  
Evgeny Nikulchev ◽  
Dmitry Ilin ◽  
Pavel Kolyasnikov ◽  
Victoria Ismatullina ◽  
Ilya Zakharov
Keyword(s):  
Hierarchical Structure ◽  
Psychological Research ◽  
Domain Specific Language ◽  
Research Needs ◽  
Web Based ◽  
Specific Language ◽  
Domain Specific ◽  
The Hierarchical Structure ◽  
General Test ◽  
Web Platform

A web platform for psychological research needs a single format of questionnaire tests to ensure interaction between its components. The study proposes a general test structure, variant questions, variations in response types, and an embedded domain-specific language for computations. The use of JSON is proposed and justified to store the hierarchical structure of the questionnaire test, and JSON Schema is defined as a technology suitable for the formation of the standard. From the considered validation instruments for compliance with the standard described in JSON Schema, ajv was defined as the most applicable to the task. To build the documentation, Doca is relevant, but this tool needs to be modified to meet the requirements of the task.

scholarly journals The Applicability of the Poincaré Plot in the Analysis of Variability of Reaction Time during Serial Testing

2021 ◽  
Vol 18 (7) ◽  
pp. 3706
Author(s):  
Elena Ioana Iconaru ◽  
Manuela Mihaela Ciucurel ◽  
Luminita Georgescu ◽  
Mariana Tudor ◽  
Constantin Ciucurel
Keyword(s):  
Reaction Time ◽  
Cross Sectional Study ◽  
Repeated Testing ◽  
Poincaré Plot ◽  
Cross Sectional ◽  
Web Based ◽  
Mean Values ◽  
Serial Testing ◽  
Reported Health ◽  
The Relationship

(1) Background: This study aims to put into evince the relationship between the variability of the reaction time (RT) during repeated testing, expressed through indicators extracted by the Poincaré plot method, and the age of the participants, their self-reported health (SRH), and level of perceived anxiety. (2) Methods: The study was performed using computerized RT testing software. An observational cross-sectional study was performed on a group of 120 subjects (mean age 42.33 ± 21.12 years), sex ratio men to women 1.14:1. Data were processed through descriptive and inferential statistics. The Poincaré plot method was applied in the analysis of the RT series of data, by calculating the indicators SD1, SD2, SD1/SD2, and area of the fitting ellipse (AFE) (3) Results: We provided evidence of the excellent reliability of the web-based RT serial testing (Cronbach’s Alpha 0.991) with this sample group. Our results showed that age is an important predictor for mean values of RT, while SD1, SD2, and AFE indicators are for SRH (p < 0.01). (4) Conclusions: the variability of RT, expressed by the Poincaré plot indicators, reflects the health status rather than the aging of the subjects and is barely influenced by their level of anxiety.

Sign in / Sign up

Export Citation Format

Share Document