Learning linear non-Gaussian graphical models with multidirected edges

Abstract In this article, we propose a new method to learn the underlying acyclic mixed graph of a linear non-Gaussian structural equation model with given observational data. We build on an algorithm proposed by Wang and Drton, and we show that one can augment the hidden variable structure of the recovered model by learning multidirected edges rather than only directed and bidirected ones. Multidirected edges appear when more than two of the observed variables have a hidden common cause. We detect the presence of such hidden causes by looking at higher order cumulants and exploiting the multi-trek rule. Our method recovers the correct structure when the underlying graph is a bow-free acyclic mixed graph with potential multidirected edges.

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Individual Characteristics as Prognostic Factors of the Evolution of Hospitalized COVID-19 Romanian Patients: A Comparative Observational Study between the First and Second Waves Based on Gaussian Graphical Models and Structural Equation Modeling

Journal of Clinical Medicine ◽

10.3390/jcm10091958 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1958

Author(s):

Alexandra Mocanu ◽

Gratiela Georgiana Noja ◽

Alin Viorel Istodor ◽

Georgiana Moise ◽

Marius Leretter ◽

...

Keyword(s):

Structural Equation Modeling ◽

Observational Study ◽

Graphical Models ◽

Structural Equation ◽

Specific Treatment ◽

Individual Characteristics ◽

Equation Modeling ◽

Gaussian Graphical Models ◽

Treatment Methods ◽

Second Wave

This study examines the role played by individual characteristics and specific treatment methods in the evolution of hospitalized patients with coronavirus disease 2019 (COVID-19), through the lens of an observational study performed in a comparative approach between the first and second waves of coronavirus pandemic in Romania. The research endeavor is configured on a two-fold approach, including a detailed observation of the evolution of 274 hospitalized patients with COVID-19 (145 in the first wave and 129 in the second wave of infection) according to specific treatment methods applied and patients’ individual features, as well as an econometric (quantitative) analysis through structural equation modeling and Gaussian graphical models designed to acknowledge the correlations and causal relationship between all considered coordinates. The main results highlight that the specific treatment methods applied had a positive influence on the evolution of COVID-19 patients, particularly in the second wave of coronavirus pandemic. In case of the first wave of COVID-19 infection, GGM results entail that there is a strong positive correlation between the evolution of the patients and the COVID-19 disease form, which is further positively correlated with the treatment scheme. The evolution of the patients is strongly and inversely correlated with the symptomatology and the ICU hospitalization. Moreover, the disease form is strongly and inversely correlated with oxygen saturation and the residence of patients (urban/rural). The symptomatology at first appearance also strongly depends on the age of the patients (positive correlation) and of the fact that the patient is a smoker or non-smoker and has other comorbidities. Age and gender are also important credentials that shape the disease degree and patient evolution in responding to treatment as well, our study attesting strong interconnections between these coordinates, the form of disease, symptomatology and overall evolution of the patients.

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MODELLING EU BIOECONOMY CREDENTIALS IN THE ECONOMIC DEVELOPMENT FRAMEWORK: THE ROLE OF INTELLECTUAL CAPITAL

Technological and Economic Development of Economy ◽

10.3846/tede.2020.13159 ◽

2020 ◽

Vol 26 (6) ◽

pp. 1139-1164

Author(s):

Mirela Cristea ◽

Graţiela Georgiana Noja ◽

Nicu Marcu ◽

Marian Siminică ◽

Diana-Mihaela Ţîrcă

Keyword(s):

Economic Development ◽

Graphical Models ◽

Intellectual Capital ◽

Structural Equation ◽

The European Union ◽

Gaussian Graphical Models ◽

Development Framework ◽

Education Innovation ◽

Innovation Patterns

Given the global importance of bioeconomy for sustainable development and its trendiness in the knowledge driven literature, our research aims to develop a general assessment framework for several shaping factors of bioeconomy fundamentals within the European Union under the decisive impact of the intellectual capital credentials, namely educational attainment, research and development activities and innovation patterns. Considering that there is a high heterogeneity among Member States (MS), selectively regarding the implementation of the intellectual capital in the knowledge economy, but also a differential degree of bioeconomy advances, we have compiled distinct panels on the two groups of EU-28 MS, namely EU-15 (old MS) and EU-13 (new MS). The purpose is to examine the inferences of the intellectual capital in the context of economic development and to shape its role in achieving a sustainable bioeconomy. We have applied several macro-econometric procedures for each considered group, namely: multifactorial macro-econometric models, structural equation modelling (SEM) and Gaussian Graphical Models (GGM), for the period 1995-2016. The results highlight that education, innovation and research, along with main bioeconomy credentials, are at the core of economic development of both EU-13 and EU-15 countries, having distinctive dissimilarities between them, particularly enhanced for the new EU-13 MS.

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Idiographic Dynamics of Positive Affect in GAD

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000580 ◽

2020 ◽

Vol 36 (3) ◽

pp. 500-509

Author(s):

Hannah G. Bosley ◽

Devon B. Sandel ◽

Aaron J. Fisher

Keyword(s):

Positive Affect ◽

Structural Equation ◽

Alternative Hypothesis ◽

Equation Model ◽

Aggregated Data ◽

Regulatory Strategy ◽

Constant State ◽

Automatic Search ◽

Time Lagged ◽

Exploratory Procedure

Abstract. Generalized anxiety disorder (GAD) is associated with worry and emotion regulation difficulties. The contrast-avoidance model suggests that individuals with GAD use worry to regulate emotion: by worrying, they maintain a constant state of negative affect (NA), avoiding a feared sudden shift into NA. We tested an extension of this model to positive affect (PA). During a week-long ecological momentary assessment (EMA) period, 96 undergraduates with a GAD analog provided four daily measurements of worry, dampening (i.e., PA suppression), and PA. We hypothesized a time-lagged mediation relationship in which higher worry predicts later dampening, and dampening predicts subsequently lower PA. A lag-2 structural equation model was fit to the group-aggregated data and to each individual time-series to test this hypothesis. Although worry and PA were negatively correlated in 87 participants, our model was not supported at the nomothetic level. However, idiographically, our model was well-fit for about a third (38.5%) of participants. We then used automatic search as an idiographic exploratory procedure to detect other time-lagged relationships between these constructs. While 46 individuals exhibited some cross-lagged relationships, no clear pattern emerged across participants. An alternative hypothesis about the speed of the relationship between variables is discussed using contemporaneous correlations of worry, dampening, and PA. Findings suggest heterogeneity in the function of worry as a regulatory strategy, and the importance of temporal scale for detection of time-lagged effects.

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Differential Item Functioning in Brief Instruments of Disordered Eating

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000472 ◽

2019 ◽

Vol 35 (6) ◽

pp. 823-833 ◽

Cited By ~ 4

Author(s):

Desiree Thielemann ◽

Felicitas Richter ◽

Bernd Strauss ◽

Elmar Braehler ◽

Uwe Altmann ◽

...

Keyword(s):

Differential Item Functioning ◽

Disordered Eating ◽

Structural Equation ◽

Young Female ◽

Eating Attitudes ◽

Equation Model ◽

German Population ◽

Test Fairness ◽

Item Functioning ◽

Multiple Indicator

Abstract. Most instruments for the assessment of disordered eating were developed and validated in young female samples. However, they are often used in heterogeneous general population samples. Therefore, brief instruments of disordered eating should assess the severity of disordered eating equally well between individuals with different gender, age, body mass index (BMI), and socioeconomic status (SES). Differential item functioning (DIF) of two brief instruments of disordered eating (SCOFF, Eating Attitudes Test [EAT-8]) was modeled in a representative sample of the German population ( N = 2,527) using a multigroup item response theory (IRT) and a multiple-indicator multiple-cause (MIMIC) structural equation model (SEM) approach. No DIF by age was found in both questionnaires. Three items of the EAT-8 showed DIF across gender, indicating that females are more likely to agree than males, given the same severity of disordered eating. One item of the EAT-8 revealed slight DIF by BMI. DIF with respect to the SCOFF seemed to be negligible. Both questionnaires are equally fair across people with different age and SES. The DIF by gender that we found with respect to the EAT-8 as screening instrument may be also reflected in the use of different cutoff values for men and women. In general, both brief instruments assessing disordered eating revealed their strengths and limitations concerning test fairness for different groups.

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The Influence of Cognitive and Affective Reactions to Feedback on Subsequent Goals

European Psychologist ◽

10.1027/1016-9040/a000011 ◽

2010 ◽

Vol 15 (2) ◽

pp. 121-131 ◽

Cited By ~ 20

Author(s):

Remus Ilies ◽

Timothy A. Judge ◽

David T. Wagner

Keyword(s):

Performance Feedback ◽

Business School ◽

Structural Equation ◽

Emotional Reactions ◽

Equation Model ◽

Proposed Model ◽

And Performance ◽

Dispositional Measure ◽

The Relationship ◽

Reactions To Feedback

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.

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Forced Zero Cross-Loading Misspecifications in Measurement Component of Structural Equation Models

Methodology ◽

10.1027/1614-2241/a000084 ◽

2014 ◽

Vol 10 (4) ◽

pp. 138-152 ◽

Cited By ~ 5

Author(s):

Hsien-Yuan Hsu ◽

Susan Troncoso Skidmore ◽

Yan Li ◽

Bruce Thompson

Keyword(s):

Structural Equation ◽

Structural Model ◽

Structural Equation Models ◽

Equation Model ◽

Model Fit ◽

Model Specification ◽

Simulation Design ◽

Measurement Models ◽

Fit Statistics ◽

Path Coefficients

The purpose of the present paper was to evaluate the effect of constraining near-zero parameter cross-loadings to zero in the measurement component of a structural equation model. A Monte Carlo 3 × 5 × 2 simulation design was conducted (i.e., sample sizes of 200, 600, and 1,000; parameter cross-loadings of 0.07, 0.10, 0.13, 0.16, and 0.19 misspecified to be zero; and parameter path coefficients in the structural model of either 0.50 or 0.70). Results indicated that factor pattern coefficients and factor covariances were overestimated in measurement models when near-zero parameter cross-loadings constrained to zero were higher than 0.13 in the population. Moreover, the path coefficients between factors were misestimated when the near-zero parameter cross-loadings constrained to zero were noteworthy. Our results add to the literature detailing the importance of testing individual model specification decisions, and not simply evaluating omnibus model fit statistics.

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