scholarly journals Sample pooling methods for efficient pathogen screening: Practical implications

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0236849
Author(s):  
Tara N. Furstenau ◽  
Jill H. Cocking ◽  
Crystal M. Hepp ◽  
Viacheslav Y. Fofanov
Keyword(s):  
Human Error ◽  
Large Scale ◽  
Group Testing ◽  
Computational Simulations ◽  
Theoretical Approaches ◽  
Testing Theory ◽  
Large Populations ◽  
Sample Pooling ◽  
Pathogen Screening ◽  
Practical Implications

Due to the large number of negative tests, individually screening large populations for rare pathogens can be wasteful and expensive. Sample pooling methods improve the efficiency of large-scale pathogen screening campaigns by reducing the number of tests and reagents required to accurately categorize positive and negative individuals. Such methods rely on group testing theory which mainly focuses on minimizing the total number of tests; however, many other practical concerns and tradeoffs must be considered when choosing an appropriate method for a given set of circumstances. Here we use computational simulations to determine how several theoretical approaches compare in terms of (a) the number of tests, to minimize costs and save reagents, (b) the number of sequential steps, to reduce the time it takes to complete the assay, (c) the number of samples per pool, to avoid the limits of detection, (d) simplicity, to reduce the risk of human error, and (e) robustness, to poor estimates of the number of positive samples. We found that established methods often perform very well in one area but very poorly in others. Therefore, we introduce and validate a new method which performs fairly well across each of the above criteria making it a good general use approach.

scholarly journals Sample pooling methods for efficient pathogen screening: Practical implications

2020 ◽  
Author(s):  
Tara N. Furstenau ◽  
Jill H. Cocking ◽  
Crystal M. Hepp ◽  
Viacheslav Y. Fofanov
Keyword(s):  
Human Error ◽  
Large Scale ◽  
Group Testing ◽  
Computational Simulations ◽  
Theoretical Approaches ◽  
Testing Theory ◽  
Large Populations ◽  
Sample Pooling ◽  
Pathogen Screening ◽  
Practical Implications

AbstractDue to the large number of negative tests, individually screening large populations for rare pathogens can be wasteful and expensive. Sample pooling methods improve the efficiency of large-scale pathogen screening campaigns by reducing the number of tests and reagents required to accurately categorize positive and negative individuals. Such methods rely on group testing theory which mainly focuses on minimizing the total number of tests; however, many other practical concerns and tradeoffs must be considered when choosing an appropriate method for a given set of circumstances. Here we use computational simulations to determine how several theoretical approaches compare in terms of (a) the number of tests, to minimize costs and save reagents, (b) the number of sequential steps, to reduce the time it takes to complete the assay, (c) the number of samples per pool, to avoid the limits of detection, (d) simplicity, to reduce the risk of human error, and (e) robustness, to poor estimates of the number of positive samples. We found that established methods often perform very well in one area but very poorly in others. Therefore, we introduce and validate a new method which performs fairly well across each of the above criteria making it a good general use approach.

scholarly journals Group testing as a strategy for COVID-19 epidemiological monitoring and community surveillance

2021 ◽  
Vol 17 (3) ◽  
pp. e1008726
Author(s):  
Vincent Brault ◽  
Bastien Mallein ◽  
Jean-François Rupprecht
Keyword(s):  
Viral Load ◽  
Statistical Model ◽  
Large Scale ◽  
Infected Individual ◽  
Group Testing ◽  
Epidemic Outbreak ◽  
False Negatives ◽  
Testing Method ◽  
Epidemiological Monitoring ◽  
Sample Pooling

We propose an analysis and applications of sample pooling to the epidemiologic monitoring of COVID-19. We first introduce a model of the RT-qPCR process used to test for the presence of virus in a sample and construct a statistical model for the viral load in a typical infected individual inspired by large-scale clinical datasets. We present an application of group testing for the prevention of epidemic outbreak in closed connected communities. We then propose a method for the measure of the prevalence in a population taking into account the increased number of false negatives associated with the group testing method.

Are There Test Administrator Effects in Large-Scale Educational Assessments?

Methodology ◽  
2007 ◽  
Vol 3 (4) ◽  
pp. 149-159 ◽  
Author(s):  
Oliver Lüdtke ◽  
Alexander Robitzsch ◽  
Ulrich Trautwein ◽  
Frauke Kreuter ◽  
Jan Marten Ihme
Keyword(s):  
Large Scale ◽  
International Student ◽  
Student Assessment ◽  
Student Groups ◽  
Mathematics Scores ◽  
International Student Assessment ◽  
Sample Attrition ◽  
Educational Assessments ◽  
Test Administrator ◽  
Practical Implications

Abstract. In large-scale educational assessments such as the Third International Mathematics and Sciences Study (TIMSS) or the Program for International Student Assessment (PISA), sizeable numbers of test administrators (TAs) are needed to conduct the assessment sessions in the participating schools. TA training sessions are run and administration manuals are compiled with the aim of ensuring standardized, comparable, assessment situations in all student groups. To date, however, there has been no empirical investigation of the effectiveness of these standardizing efforts. In the present article, we probe for systematic TA effects on mathematics achievement and sample attrition in a student achievement study. Multilevel analyses for cross-classified data using Markov Chain Monte Carlo (MCMC) procedures were performed to separate the variance that can be attributed to differences between schools from the variance associated with TAs. After controlling for school effects, only a very small, nonsignificant proportion of the variance in mathematics scores and response behavior was attributable to the TAs (< 1%). We discuss practical implications of these findings for the deployment of TAs in educational assessments.

The Use of Medical Record Linkage for Population and Genetic Studies

1969 ◽  
Vol 08 (01) ◽  
pp. 07-11 ◽  
Author(s):  
H. B. Newcombe
Keyword(s):  
Record Linkage ◽  
Large Scale ◽  
Medical Record Linkage ◽  
Canadian Province ◽  
Genetic Studies ◽  
Parental Characteristics ◽  
Family Histories ◽  
The Family ◽  
Large Populations ◽  
Machine Readable

Methods are described for deriving personal and family histories of birth, marriage, procreation, ill health and death, for large populations, from existing civil registrations of vital events and the routine records of ill health. Computers have been used to group together and »link« the separately derived records pertaining to successive events in the lives of the same individuals and families, rapidly and on a large scale. Most of the records employed are already available as machine readable punchcards and magnetic tapes, for statistical and administrative purposes, and only minor modifications have been made to the manner in which these are produced.As applied to the population of the Canadian province of British Columbia (currently about 2 million people) these methods have already yielded substantial information on the risks of disease: a) in the population, b) in relation to various parental characteristics, and c) as correlated with previous occurrences in the family histories.

How “The Three Rules” guide strategy and investment decisions at Deloitte Consulting LLP

2015 ◽  
Vol 43 (3) ◽  
pp. 7-14 ◽  
Author(s):  
Jim Moffatt
Keyword(s):  
Design Methodology ◽  
Large Scale ◽  
Investment Decisions ◽  
Decision Makers ◽  
Research Project ◽  
Content Type ◽  
First Case ◽  
Practical Implications ◽  
Thought Leadership

Purpose – This case example looks at how Deloitte Consulting applies the Three Rules synthesized by Michael Raynor and Mumtaz Ahmed based on their large-scale research project that identified patterns in the way exceptional companies think. Design/methodology/approach – The Three Rules concept is a key piece of Deloitte Consulting’s thought leadership program. So how are the three rules helping the organization perform? Now that research has shown how exceptional companies think, CEO Jim Moffatt could address the question, “Does Deloitte think like an exceptional company?” Findings – Deloitte has had success with an approach that promotes a bias towards non-price value over price and revenue over costs. Practical implications – It’s critical that all decision makers in an organization understand how decisions that are consistent with the three rules have contributed to past success as well as how they can apply the rules to difficult challenges they face today. Originality/value – This is the first case study written from a CEO’s perspective that looks at how the Three Rules approach of Michael Raynor and Mumtaz Ahmed can foster a firm’s growth and exceptional performance.

Math coaches, specialists, and student achievement: Learning from the data

2020 ◽  
Vol 102 (3) ◽  
pp. 42-45
Author(s):  
Kristin E. Harbour ◽  
Evthokia Stephanie Saclarides
Keyword(s):  
Student Achievement ◽  
Teaching And Learning ◽  
Large Scale ◽  
Elementary Mathematics ◽  
National Assessment ◽  
Mathematics Coaches ◽  
Professional Development Model ◽  
Using Data ◽  
The Relationship ◽  
Practical Implications

To support continuous professional development model in the teaching and learning of mathematics, many districts and schools have begun hiring elementary mathematics coaches and/or specialists (MCSs). However, limited large-scale empirical research exists that determines how the use of MCSs affect student learning and achievement. Kristin E. Harbour and Evthokia Stephanie Saclarides begin to fill in this gap by using data from the National Assessment of Educational Progress to explore the relationship between the presence and responsibilities of elementary MCSs and 4th-grade student achievement in mathematics. Based on their findings, they share practical implications for districts and administrators to consider.

Nitrogen from the atmosphere to the crop

1983 ◽  
Vol 12 (2) ◽  
pp. 90-97 ◽  
Author(s):  
P. P. King
Keyword(s):  
Large Scale ◽  
Crop Plants ◽  
Intensive Agriculture ◽  
Nitrogen Fixing ◽  
Biological Fixation ◽  
Traditional Methods ◽  
The Cost ◽  
Practical Implications

During the middle decades of this century large-scale intensive agriculture relied heavily on the availability of cheap synthetic nitrogenous fertilisers. Little attention then had to be paid to the cost of the energy involved in the manufacture and use of fertilisers, but in recent years this factor has become of major importance. This article reviews the practical implications of the energetics of chemical and biological fixation of nitrogen and the utilisation of nitrogen by various crop plants. It reaches a number of interesting conclusions, including one that even if biotechnology made nitrogen-fixing cereals available, they would not necessarily be competitive with normal cereals produced by traditional methods. This is, however, not necessarily true of grass.

Strengthening the Norms of Global Responsibility: Structural Violence in Relation to Internal Displacement and Statelessness

2012 ◽  
Vol 4 (4) ◽  
pp. 475-504 ◽  
Author(s):  
Lindsey N. Kingston ◽  
Saheli Datta
Keyword(s):  
Large Scale ◽  
Physical Violence ◽  
Structural Violence ◽  
International Community ◽  
Internal Displacement ◽  
Internally Displaced ◽  
Global Responsibility ◽  
Cultural Violence ◽  
Starting Point ◽  
Large Populations

Norms of global responsibility have changed significantly since the 1948 Universal Declaration of Human Rights (UDHR), and today’s international community critically considers responsibilities within and beyond state borders, as evidenced by the adoption of the Responsibility to Protect (R2P) doctrine. From this starting point, protection must be extended to large populations susceptible to structural violence – social harms resulting from the pervasive and persistent impact of economic, political and cultural violence in societies. In order to show the potential of expanded conceptions of global responsibility, this article proceeds as follows: First, a discussion of the evolving concepts of responsibility outlines a shift in thinking about sovereignty that creates a multilayered system of responsibility. This section defines key concepts and highlights an ‘unbundled R2P’ framework for approaching structural violence. Second, an overview of two vulnerable populations – internally displaced persons (IDPs) and the stateless – illustrates that large-scale cases of state abuse and neglect are not limited to acts of physical violence, and that pervasive structural violence requires further attention from the international community. Lastly, recommendations are provided for expanding the scope of global responsibility in order to assist the internally displaced and the stateless. These recommendations address who is responsible, when global responsibility is warranted, and how such responsibility should be implemented.

scholarly journals A networked voting rule for democratic representation

2018 ◽  
Vol 5 (3) ◽  
pp. 172265 ◽  
Author(s):  
Alexis R. Hernández ◽  
Carlos Gracia-Lázaro ◽  
Edgardo Brigatti ◽  
Yamir Moreno
Keyword(s):  
Large Scale ◽  
Selection Process ◽  
General Relation ◽  
Community Size ◽  
Rule Based ◽  
Voting Rule ◽  
Large Populations ◽  
Negative Effect ◽  
High Connectivity ◽  
Better Than

We introduce a general framework for exploring the problem of selecting a committee of representatives with the aim of studying a networked voting rule based on a decentralized large-scale platform, which can assure a strong accountability of the elected. The results of our simulations suggest that this algorithm-based approach is able to obtain a high representativeness for relatively small committees, performing even better than a classical voting rule based on a closed list of candidates. We show that a general relation between committee size and representatives exists in the form of an inverse square root law and that the normalized committee size approximately scales with the inverse of the community size, allowing the scalability to very large populations. These findings are not strongly influenced by the different networks used to describe the individuals’ interactions, except for the presence of few individuals with very high connectivity which can have a marginal negative effect in the committee selection process.

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