An Approach to the Design and Analysis of Screening Studies in Toxicology

1988 ◽  
Vol 7 (2) ◽  
pp. 127-138 ◽  
Author(s):  
S.C. Gad
Keyword(s):  
Statistical Analysis ◽  
Historical Data ◽  
Screening Tests ◽  
Test Case ◽  
Operating Characteristics ◽  
Analysis Process ◽  
Exploratory Data ◽  
Alternative Approaches ◽  
Traditional Approaches ◽  
Neurobehavioral Effects

An increasingly important aspect of toxicology is the use of screening tests for detecting the presence or absence of a single end point of effect, such as mutagenicity or neurobehavioral effects. Such screens have a common set of operating characteristics that are not widely apreciated and that make traditional approaches to statistical analysis insensitive and inefficient in comparison to other available methods. All too often, control and historical data are not used to strengthen the analysis process. The characteristics of screens are presented and reviewed, along with overviews of 26 sets of data from functional observational battery screen (neurobehavioral) studies. Two alternative approaches to statistical analysis of screening tests (a control chart approach and a graphic-exploratory data analysis approach) are presented, along with a review of traditionally used contingency table, rank sum, and ANOVA methods. The performances of these methods in analyzing the test case screen datasets are compared in terms of power, sensitivity, and efficiency. Both alternative approaches are shown to be superior to traditional approaches in performance toward meeting the objectives of screens.

Principles of Screening in Toxicology with Special Emphasis on Applications to Neurotoxicology

1989 ◽  
Vol 8 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Shayne C. Gad
Keyword(s):  
Exploratory Data Analysis ◽  
Historical Data ◽  
Screening Tests ◽  
Operating Characteristics ◽  
Major Activity ◽  
Exploratory Data ◽  
Low Probability ◽  
Traditional Approaches ◽  
Neurobehavioral Effects ◽  
Special Case

It is not generally recognized that the major activity or function of classic descriptive toxicology is the use of screening tests for detecting the presence or absence of an effect, Generally, such screens have been directed at the detection of a single end point of effect, such as lethality, mutagenicity, or neurobehavioral effects. Such screens have a common set of operating characteristics that are not widely appreciated and that make traditional approaches to statistical analysis insensitive and inefficient in comparison to other available methods. Also, all too often control and historical data are not incorporated to strengthen either the design or analysis processes. Just as often overlooked is the intended objective or function of a screen, which acts as the biologic equivalent of a form of exploratory data analysis (EDA). As such, screens act to identify areas-compounds (i.e., explore or discover responses) that then either require further research (to confirm the existence of an effect and evaluate the relevance of any hazard to humans) or pass a compound on as representing low probability of a hazard. This fundamental discovery function forces screens to be designed to be very sensitive and, in so doing, requires that positive findings be understood to be flags that say “Look here” (and not that a material is, for example, a neurotoxicant). Discrimination, in other words, though important, is secondary. In this article, the characteristics and uses of screens in toxicology are presented and reviewed, along with overviews of the types and philosophy of screening operations. The relevance of these factors to the special case of neurotoxicology is pointed out, with specific examples and implications.

Statistical Analysis of Screening Studies in Toxicology with Special Emphasis on Neurotoxicology

1989 ◽  
Vol 8 (1) ◽  
pp. 171-183 ◽  
Author(s):  
Shayne C. Gad
Keyword(s):  
Statistical Analysis ◽  
Control Charts ◽  
Additional Data ◽  
Central Tendency ◽  
Operating Characteristics ◽  
Traditional Methods ◽  
Factors Influencing ◽  
Alternative Approaches ◽  
Principles Of Design ◽  
Traditional Approaches

Screens have a common set of operating characteristics that are not widely appreciated and that make traditional approaches to statistical analysis both insensitive and inefficient in comparison to other available methods. Traditional methods also do not incorporate additional data as it is generated. Such incorporation would serve to strengthen both the design and analysis processes and is essential in the case of screens. Traditional methods of analysis (contingency tables, rank sum, and ANOVA methods) are overviewed briefly, and their weaknesses are discussed. The concept of power and the factors influencing it are discussed. Alternative approaches to analysis of univariate (control charts and central tendency plots) and multivariate (analog contrast plots and multidimensional cluster plots) data from screens are presented, and their performance is evaluated. The resulting general principles of design and analysis of screens for neurotoxicology are presented. The alternative approaches are shown to be superior to traditional approaches in performance toward meeting the objectives of screens.

Screens in Neurotoxicity: Objectives, Design, and Analysis, with the Functional Observational Battery as a Case Example

1989 ◽  
Vol 8 (2) ◽  
pp. 287-301 ◽  
Author(s):  
Shayne C. Gad
Keyword(s):  
Data Analysis ◽  
Initial Phase ◽  
Screening Tests ◽  
Operating Characteristics ◽  
Design Features ◽  
End Point ◽  
Alternative Approaches ◽  
Study Designs ◽  
Relationship Of ◽  
Functional Observational Battery

Screening tests for detecting the presence or probable absence of a single end point (such as neurobehavioral activity) are the most common and important activities in toxicology. Objectives and characteristics of screens are presented and reviewed here, and the corresponding essential design features of a neurotoxicology screen are suggested. It is pointed out that such screens should function as the initial phase in some form of multitier process and that they would be most efficiently and effectively performed and accurately interpreted by incorporation into existing study designs. Also presented are the objectives of an analysis of data from screens and the essential relationship of such analysis to those objectives. The types of data encountered are reviewed, along with traditional and alternative approaches to data analysis and their operating characteristics. Finally, the different current forms of neurotoxicity screens (both primary and secondary) are summarized. The functional observational battery and its history, performance, and limitations are presented in light of the proposed principles as an example case for screening.

scholarly journals Digitizing practical production work for high-stakes assessments / La numérisation de travaux pratiques de production pour les évaluations à enjeux élevés / La numérisation de travaux pratiques de production pour les évaluations à enjeux élevés

2014 ◽  
Vol 40 (2) ◽  
Author(s):  
Paul Newhouse ◽  
Pina Tarricone
Keyword(s):  
Digital Technologies ◽  
Creative Expression ◽  
Practical Work ◽  
Viable Alternative ◽  
Validity And Reliability ◽  
High Stakes ◽  
External Assessment ◽  
Digital Representations ◽  
Alternative Approaches ◽  
Traditional Approaches

High-stakes external assessment for practical courses is fraught with problems impacting on the manageability, validity and reliability of scoring. Alternative approaches to assessment using digital technologies have the potential to address these problems. This paper describes a study that investigated the use of these technologies to create and submit digital representations of practical production work and forms of creative expression for summative high-stakes assessment. The study set out to determine the feasibility of students creating and submitting these digital representations for assessment and to identify which of analytical or comparative pairs scoring generated the more reliable scores. This paper proposes that scoring digital representations of creative practical work submitted by students is a viable alternative to traditional approaches to assessment. L’évaluation externe à enjeux élevés dans les cours pratiques se heurte à des problèmes qui se répercutent sur la gestion, la validité et la fiabilité de la notation. Des approches différentes de l'évaluation utilisant des technologies numériques ont le potentiel de remédier à ces problèmes. Cet article décrit une étude consacrée à l'utilisation de ces technologies pour créer et soumettre des représentations numériques de travaux pratiques de production et de création pour une évaluation sommative à enjeux élevés. L'étude visait à déterminer si la création de ces représentations numériques par les étudiants et leur soumission pour évaluation étaient réalisables. Elle visait aussi à identifier quel système de notation de groupe, analytique ou comparatif, générait les scores les plus fiables. Cet article soutient que noter les représentations numériques de travaux pratiques soumis par les étudiants offre un choix viable aux approches traditionnelles d'évaluation.

scholarly journals Evaluation of sodium lauryl sulfate for the development of cow-side mastitis screening test

2021 ◽  
pp. 2290-2295
Author(s):  
Nobonita Sarker Tanni ◽  
Md. Shafiul Islam ◽  
Mojahidul Kabir ◽  
Mst. Sonia Parvin ◽  
Md. Amimul Ehsan ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Sodium Lauryl Sulfate ◽  
Early Stage ◽  
High Sensitivity ◽  
Subclinical Mastitis ◽  
Screening Tests ◽  
Bromocresol Purple ◽  
Lauryl Sulfate ◽  
Operating Characteristics ◽  
Milk Samples

Background and Aim: Subclinical mastitis (SCM) is an economically important disease for dairy cattle worldwide; therefore, regular screening is imperative to detect SCM at an early stage so as to control it. The study was conducted to compare the test characteristics of sodium lauryl sulfate (SLS) as a test reagent to detect SCM in dairy cows. Materials and Methods: First, 106 milk samples of dairy cows were subjected to available indirect screening tests (white side test [WST], surf field mastitis test, Leucocytest, and Immucell) considering somatic cell count (SCC) as gold standard test. Then 273 milk samples were allowed to react with different concentrations of SLS with or without sodium hydroxide (NaOH) and indicators (bromothymol blue [BTB] and bromocresol purple [BCP]). Results: SLS with or without NaOH yielded best reaction with the milk samples similar to Leucocytest. It was observed that the reaction of milk samples with SLS added with indicators (BTB and BCP) was easier to visualize than without indicators. SLS 3%+NaOH 1.5% with BTB and SLS 2% with BCP had high sensitivity, specificity, and substantial agreement with SCC. The area under the receiver operating characteristics curve of SLS 2% with BCP and SLS 3%+NaOH 1.5% with BTB was 0.917 and 0.875, respectively. Conclusion: It may be concluded that SLS 3%+NaOH 1.5% with BTB and SLS 2% with BCP may be the potential reagents for the development of an effective cow-side test to detect SCM, as the main ingredient SLS is considerably cheap and readily available in developing countries.

The Role of Management Accounting Systems in Public Hospitals and the Construction of Budgets

2016 ◽  
pp. 366-389
Author(s):  
Carla Marina Pereira de Campos ◽  
Lúcia Lima Rodrigues ◽  
Susana Margarida Faustino Jorge
Keyword(s):  
Management Accounting ◽  
Health Sector ◽  
Public Hospitals ◽  
Public Funds ◽  
Accounting Systems ◽  
The Public ◽  
Management Accounting Systems ◽  
Alternative Approaches ◽  
Traditional Approaches

The role of management accounting systems (MAS) in the construction of budgets in the public health sector has been one of the least studied topics in the international literature. Furthermore, several studies have confirmed the loss of relevance of traditional approaches to budgeting due to the need to implement techniques that are more performance-oriented. Since public hospitals are organisations that depend significantly on public funds, with substantial impacts on governments' budgets, the pressure for reducing expenditures is strong, causing increased difficulties in hospital management. In order to analyse the role of MAS in the preparation of hospital budgets, this chapter presents a literature review on this topic. This review allows to understand the loss of relevance of traditional budgeting techniques and to present alternative approaches. In this process, the implementation of different kinds of budgeting is heavily influenced by governments and professionals. Nevertheless, the research on this topic is still very scarce, evidencing the need to continue studying it.

2. IR as an Academic Subject

2018 ◽  
pp. 33-66
Author(s):  
Robert Jackson ◽  
Georg Sørensen ◽  
Jørgen Møller
Keyword(s):  
International Political Economy ◽  
First World War ◽  
Good Theory ◽  
World War ◽  
The Third ◽  
Academic Subject ◽  
The First World War ◽  
Alternative Approaches ◽  
Traditional Approaches ◽  
First World

This chapter examines how thinking about international relations (IR) has evolved since IR became an academic subject around the time of the First World War. The focus is on four established IR traditions: realism, liberalism, International Society, and International Political Economy (IPE). The chapter first considers three major debates that have arisen since IR became an academic subject at the end of the First World War: the first was between utopian liberalism and realism; the second between traditional approaches and behaviouralism; the third between neorealism/neoliberalism and neo-Marxism. There is an emerging fourth debate, that between established traditions and post-positivist alternatives. The chapter concludes with an analysis of alternative approaches that challenge the established traditions of IR, and with a discussion about criteria for good theory in IR.

2. IR as an Academic Subject

2015 ◽  
Author(s):  
Robert Jackson ◽  
Georg Sørensen
Keyword(s):  
Political Economy ◽  
International Political Economy ◽  
First World War ◽  
World War ◽  
The Third ◽  
Academic Subject ◽  
The First World War ◽  
Alternative Approaches ◽  
Traditional Approaches ◽  
First World

This chapter examines how thinking about international relations (IR) has evolved since IR became an academic subject around the time of the First World War. The focus is on four established IR traditions: realism, liberalism, International Society, and International Political Economy (IPE). The chapter first considers three major debates that have arisen since IR became an academic subject at the end of the First World War: the first was between utopian liberalism and realism; the second between traditional approaches and behaviouralism; the third between neorealism/neoliberalism and neo-Marxism. There is an emerging fourth debate, that between established traditions and post-positivist alternatives. The chapter concludes with an analysis of alternative approaches that challenge the established traditions of IR.

Overview of Author Cocitation Analysis Procedures

2010 ◽  
pp. 144-170
Author(s):  
Sean Eom
Keyword(s):  
Statistical Analysis ◽  
Multivariate Statistical Analysis ◽  
Multivariate Statistical ◽  
Cocitation Analysis ◽  
Alternative Approaches ◽  
Author Cocitation ◽  
Frequency Counts ◽  
Selection Of ◽  
Author Cocitation Analysis

The previous two chapters examined the two alternative approaches of retrieving cocitation counts using custom databases and cocitation frequency counts extraction systems. The cocitaion frequency counts are the inputs to the SAS or SPSS systems for multivariate statistical analysis. The primary purpose of this chapter is to overview several important steps in author cocitation analysis. ACA consists of the six major steps beginning with the selection of author sets for further analysis, then collection of cocitation frequency counts, statistical analysis of the cocitation frequency counts, and the validation and interpretation of statistical outputs.

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