scholarly journals Bayes Factors for Mixed Models

2021 ◽  
Author(s):  
Johnny van Doorn ◽  
Frederik Aust ◽  
Julia M. Haaf ◽  
Angelika Stefan ◽  
Eric-Jan Wagenmakers

Although Bayesian mixed models are increasingly popular for data analysis in psychology and other fields, there remains considerable ambiguity on the most appropriate Bayes factor hypothesis test to quantify the degree to which the data support the presence or absence of an experimental effect. Specifically, different choices for both the null model and the alternative model are possible, and each choice constitutes a different definition of an effect resulting in a different test outcome. We outline the common approaches and focus on the impact of aggregation, the effect of measurement error, the choice of prior distribution, and the detection of interactions. For concreteness, three example scenarios showcase how seemingly innocuous choices can lead to dramatic differences in statistical evidence. We hope this work will facilitate a more explicit discussion about best practices in Bayes factor hypothesis testing in mixed models.

Author(s):  
Johnny van Doorn ◽  
Frederik Aust ◽  
Julia M. Haaf ◽  
Angelika M. Stefan ◽  
Eric-Jan Wagenmakers

AbstractAlthough Bayesian linear mixed effects models are increasingly popular for analysis of within-subject designs in psychology and other fields, there remains considerable ambiguity on the most appropriate Bayes factor hypothesis test to quantify the degree to which the data support the presence or absence of an experimental effect. Specifically, different choices for both the null model and the alternative model are possible, and each choice constitutes a different definition of an effect resulting in a different test outcome. We outline the common approaches and focus on the impact of aggregation, the effect of measurement error, the choice of prior distribution, and the detection of interactions. For concreteness, three example scenarios showcase how seemingly innocuous choices can lead to dramatic differences in statistical evidence. We hope this work will facilitate a more explicit discussion about best practices in Bayes factor hypothesis testing in mixed models.


2021 ◽  
Vol 10 (8) ◽  
pp. 1740
Author(s):  
Marion Bareille ◽  
Michaël Hardy ◽  
Jonathan Douxfils ◽  
Stéphanie Roullet ◽  
Dominique Lasne ◽  
...  

Infection by SARS-CoV-2 is associated with a high risk of thrombosis. The laboratory documentation of hypercoagulability and impaired fibrinolysis remains a challenge. Our aim was to assess the potential usefulness of viscoelastometric testing (VET) to predict thrombotic events in COVID-19 patients according to the literature. We also (i) analyzed the impact of anticoagulation and the methods used to neutralize heparin, (ii) analyzed whether maximal clot mechanical strength brings more information than Clauss fibrinogen, and (iii) critically scrutinized the diagnosis of hypofibrinolysis. We performed a systematic search in PubMed and Scopus databases until December 31st, 2020. VET methods and parameters, and patients’ features and outcomes were extracted. VET was performed for 1063 patients (893 intensive care unit (ICU) and 170 non-ICU, 44 studies). There was extensive heterogeneity concerning study design, VET device used (ROTEM, TEG, Quantra and ClotPro) and reagents (with non-systematic use of heparin neutralization), timing of assay, and definition of hypercoagulable state. Notably, only 4 out of 25 studies using ROTEM reported data with heparinase (HEPTEM). The common findings were increased clot mechanical strength mainly due to excessive fibrinogen component and impaired to absent fibrinolysis, more conspicuous in the presence of an added plasminogen activator. Only 4 studies out of the 16 that addressed the point found an association of VETs with thrombotic events. So-called functional fibrinogen assessed by VETs showed a variable correlation with Clauss fibrinogen. Abnormal VET pattern, often evidenced despite standard prophylactic anticoagulation, tended to normalize after increased dosing. VET studies reported heterogeneity, and small sample sizes do not support an association between the poorly defined prothrombotic phenotype of COVID-19 and thrombotic events.


1987 ◽  
Vol 17 (4) ◽  
pp. 369-393
Author(s):  
Selden D. Bacon

In view of the low likelihood of the acceptance of the social science approach to alcohol problems proposed several years ago, a “common sense” approach is suggested as an alternative. Several assumptions guide this proposal, the principal one being the absence of any significant progress in the reduction of alcohol problems in the United States over the past 200 years. By the development of a common vocabulary and direct methods of observation and data collection, the “common sense” approach would provide for identifying the strengths of the multitude of past and current efforts in dealing with alcohol problems in terms of both intervention and prevention. The guiding criterion in such an approach would be the impact on alcoholism and alcohol-related problems, the definition of which would be a major task of the research.


2019 ◽  
Vol 13 (13) ◽  
pp. 1081-1091
Author(s):  
Judith van Paassen ◽  
Jaap T van Dissel ◽  
Pieter S Hiemstra ◽  
Jaap Jan Zwaginga ◽  
Christa M Cobbaert ◽  
...  

Aim: Biomarkers of acute respiratory distress syndrome (ARDS) after cardiac-surgery may help risk-stratification and management. Preoperative single-value proADM increases predictive capacity of scoring-system EuroSCORE. To include the impact of surgery, we aim to assess the predictive value of the perioperative proADM-change on development of ARDS in 40 cardiac-surgery patients. Materials & methods: ProADM was measured in nine sequential blood samples. The Berlin definition of ARDS was used. For data-analyses, a multivariate model of EuroSCORE and perioperative proADM-change, linear mixed models and logistic regression were used. Results: Perioperative proADM-change was associated with ARDS after cardiac-surgery, and it was superior to EuroSCORE. A perioperative proADM-change >1.5 nmol/l could predict ARDS. Conclusion: Predicting post-surgery ARDS with perioperative proADM-change enables clinicians to intensify lung-protective interventions and individualized fluid therapy to minimize secondary injury.


Lex Russica ◽  
2020 ◽  
pp. 28-40
Author(s):  
V. N. Ivakin

The main form of protection of civil rights (in the broad sense) is the form of action bringing, the impact of which has increased significantly as a result of the transition to a market economy. This form has gained even wider application with the adoption of the Code of Administrative Procedure of the Russian Federation of March 8, 2015, that has introduced the institution of an administrative action in relation to cases arising from administrative and other relations regulated in the context of public law. However, the question concerning the concept of the action, regarding which in the legal science several concepts are being applied, remains unclear and the paper examines different concepts dealing with the notion of the action. In particular, according to the author, the term “action” does not mean a legal act. This view is based on the common identification of the Russian term “isk” with the Latin term actio that literally meaning “action.” The article also subjects to extensive criticism an outdated doctrine about the action in procedural and substantive senses. Attention is also drawn to the shortcomings of the doctrine that treats the action as the unity of the two parties — procedural (the applicant’s claim to the court) and substantive (the applicant’s claim to the defendant). The author has examined the inconsistency of the doctrine of the lawsuit developed by G. L. Osokina treating the action as the claim to protect a right and at the same time to admit the existence of the right to bring an action in a procedural and substantive sense. Also, the article analyzes the shortcomings of the definitions of the action given by V. V. Yarkov and O. V. Isaenkova. In conclusion, the author substantiates and gives his own definition of the concept of the action as the request addressed to court by the person concerned, submitted and considered in a certain procedural order in order to protect the violated right. The concept under consideration is also defined as the right that requires confirmation, freedom or legitimate interest and the direct exercise of the right or the satisfaction of a legitimate interest for which another person is held liable.


Author(s):  
Alexis Ronney ◽  
Benjamin J. Kirby

Purpose Service-learning has the potential to improve student outcomes by providing students opportunities to apply their knowledge and skills in real-world contexts and is well suited to graduate education in communication sciences and disorders. However, relatively few service-learning studies in the literature focus on audiology, and the range of outcomes specific to audiology service-learning has not yet been characterized in a systematic way. The purpose of this critical review was to characterize the impact of service-learning on audiology students and clients/patients as evidenced by reflection activities and outcome measures, as well as to describe the common challenges and best practices in the available literature that may inform future research on service-learning in the field. Method A systematic search of the literature using multiple databases was completed according to standard guidelines. The impact of each study was evaluated using a standard scale of training efficacy. Study methods, including reflection activities and outcome measures, were recorded. Results Nine peer-reviewed studies on service-learning in audiology were selected. Six of the nine studies reported changes in student attitudes or awareness related to issues of clinical practice; five of the nine studies reported improvements in student knowledge/skills. Conclusions Overall, results of the review indicated benefits of service-learning to student clinicians. However, evidence for transference of service-learning benefits to organizational or departmental practice and benefit to patients/clients was lacking. Methodological limitations in the measurement of outcomes in prior works complicated evaluation of their impact; best practices were identified and synthesized for use in future research on audiology service-learning experiences.


Author(s):  
Paul S. Davies ◽  
Graham Virgo

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. Equity & Trusts: Text, Cases, and Materials provides a guide to the subject by providing analyses of the law of equity and trusts with extracts from cases and materials. This book provides analysis of significant recent key cases including the Supreme Court’s decision in Patel v Mirza where a new approach to determining the impact of the taint of illegality on private law claims was identified, which is of particular significance to claims for breach of trust and the recognition of the resulting trust. Other relevant decisions include: Angove’s Pty Ltd v Bailey, on the recognition of the constructive trust; Akers v Samba Financial Corp, on the nature of proprietary interests and rights under trusts; Ivey v Genting Casinos UK Ltd (t/a Crockfords Club), on the definition of dishonesty; and Burnden Holdings (UK) Ltd v Fielding, on limitation periods. Similarly, the Privy Council has heard important appeals in the area of Equity and trusts: notably Investec Trust (Guernsey) Ltd v Glenala Properties, on trustees and breach of trust and Marr v Collie, on the recognition of the common intention constructive trust. The impact of these developments has meant that there has been particularly significant rewriting of chapter 7 (constructive trusts) and chapter 9 (informal arrangements relating to land), plus significant rewriting of sections in other chapters, especially as to the nature of the rights and interests under a trust and the effect of illegality. The book is made up of nine parts that consider express private trusts, purpose trusts, non-express trusts, beneficiaries, trusties, variation, breach, and orders.


2008 ◽  
Vol 57 (3) ◽  
Author(s):  
Antonio G. Spagnolo ◽  
Viviana Daloiso

Il presente articolo intende inquadrare e definire le implicazioni etiche riguardanti l’applicazione biomedica delle nanotecnologie, attraverso la valutazione dello stato dell’arte. Le nanotecnologie, espressione dell’abilità umana di manipolare la materia su scala atomico/molecolare, si presentano come uno strumento in grado di modificare la ricerca scientifica e la medicina in maniera radicale. Dibattiti ad ogni livello hanno sottolineato la difficoltà di darne una definizione chiara ed univoca, a causa della convergenza di più ambiti del sapere in esse coinvolti. Nonostante le nanotecnologie siano già presenti nelle scienze computeristiche e nell’elettronica, è in ambito medico-sanitario che si prospettano le applicazioni più entusiasmanti: strumenti di diagnosi e somministrazione di farmaci meno invasivi e più efficaci. Queste tecnologie si presentano infatti allo stesso tempo come terapie ma anche come strumenti di prevenzione unici. Le stesse caratteristiche che rendono singolare l’impiego delle nanotecnologie in medicina, suggeriscono altresì precauzioni: da una parte infatti la di mensione piccolissima (atomico-molecolare) delle nanoparticelle facilita il loro ingresso nell’organismo umano, oltrepassando le difese naturali dell’organismo, agevolando una distribuzione dei farmaci altamente mirata. Dall’altra parte queste stesse caratteristiche posso rivelarsi dannose per l’organismo umano (interazione tra nanoparticelle e sistema biologico umano, elevato rapporto tra massa e superficie, mobilità). Poiché si tratta di tecnologie in rapida progressione i cui sviluppi non sono facili da predire, i rischi, anche solo quelli potenziali, devono essere accuratamente valutati sia per le applicazioni presenti sia per quelle future. Pertanto inquadrare le implicazioni bioetiche delle nanotecnologie significa comprendere e valutare il loro impatto sulla salute umana. ---------- The aim of this contribution is to outline and define some ethical implications concerning biomedical applications of nanotechnologies. Nanotechnology, expression of the human ability to manipulate matter on a molecular and atomic scale, provide an instrument able to change scientific research and medicine in a radical way. Debate at all levels have pointed out the common difficulty to give a clear and univocal definition of nanotechnologies, due to the convergence of technologies there involved. Although these technologies have already been implemented in electronics or computer science, the most useful ones are foreseen to be in new approaches for research purposes and medicine, providing diagnosis and drug delivery with no invasive methods involved. These technology, in fact, look like therapy but they also represent unique prevention tools. The very same characteristics that make nanomaterial useful in medicine, suggest some precaution: o one hand, thanks to their small size (atomic dimension) nanoparticles can enter cells in the organisms, avoiding natural defenses and move to organs and tissues allowing a target distribution of drugs. On the other hand, these technologies can turn to be harmful to humans (interaction between nanoparticles and the biological human system, high surface- to-mass relation, mobility). Because we are dealing with a rapidly developing technology, where most of the effects are still hard to foresee, potential risks must be considered for both current and future applications. So far, outlining ethical issues means understanding the impact of these technologies on human health.


Author(s):  
Richard Glover

This chapter provides an overview of the law of evidence. It discusses the definition of evidence and how the law of evidence differs from the science or philosophy of evidence; the characteristics of the judicial trial that demand a particular legal approach to the presentation and use of evidence including, on occasion, its exclusion; the development of the rules of evidence in the common law system and the factors that influenced this; the classification of the rules of evidence; and the impact of the European Convention on Human Rights, in particular the provisions relating to the right to a fair trial.


2019 ◽  
Vol 8 (9) ◽  
pp. 563-566 ◽  
Author(s):  
Jillian Clare Kohler

In this commentary, I argue that corruption in health systems is a critical and legitimate area for research in order to strengthen health policy goals. This rationale is based partly on citizen demand for more accountable and transparent health systems, along with the fact that the poor and vulnerable suffer the most from the presence of corruption in health systems. What is more, there is a growing body of literature on the impact of corruption in the health system and best practices in terms of anti-corruption, transparency and accountability (ACTA) strategies and tactics within the health system. Still, we need to support ACTA integration into the health system by having a common definition of corruption that is meaningful for health systems and ensure that ACTA strategies and tactics are transparent themselves. The 2019 Consultation on a proposed Global Network on ACTA in Health Systems is promising for these efforts.


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