1,721,002 research outputs found
The influence of school size, principal characteristics and school management practices on educational performance: An efficiency analysis of Italian students attending middle schools
Get PDFThe aim of the paper is to identify which among the aspects that relate to the composition of the student body, school (district) size, management practices and the school principals' own characteristics are associated with the performance of Italian students at grade 8, measured through standardised test scores in reading and mathematics. The analysis makes use of a student-level efficiency model, and several school level variables are included as explanators for efficiency scores. The results show that, especially for reading, the most influential variables relate to the composition of the student body, while the students' performance in mathematics is partly correlated with the management practices adopted by the school principal/head teacher. Schools and schooling can only explain a minor part of the variance in achievement scores, however, and the characteristics of the students themselves play the most significant role
Using regression tree ensembles to model interaction effects: a graphical approach
Get PDFMultiplicative interaction terms are widely used in economics to identify heterogeneous effects and to tailor policy recommendations. The execution of these models is often flawed due to specification and interpretation errors. This article introduces regression trees and regression tree ensembles to model and visualize interaction effects. Tree-based methods include interactions by construction and in a nonlinear manner. Visualizing nonlinear interaction effects in a way that can be easily read overcomes common interpretation errors. We apply the proposed approach to two different datasets to illustrate its usefulness
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Malocclusion and perinatal factors: A retrospective study
No full textAim: To evaluate the relationship between perinatal risk factors, including use of pro-and antilabordrugs, and development of dental malocclusion. Methods: Forthis retrospective cohort study, 31 patients with malocclusion (test group) and 31 control subjects were recruited.All study participants were children (aged 6-8 years) with deciduous or mixed dentition. The children’s mothers responded to a questionnaire regarding their perinatal experiences, which was administered byan interviewer who was blinded to the study aim. Following identification of significantly associated variables by univariate analysis, potentially confounding variables were included in the multivariate analysis of significant variables to account for possible bias. Results: No association between breastfeeding and childhood malocclusion risk was found. Pregnancy less than 9 months appeared to enhance malocclusion risk(odds ratio [OR]: 3.48) despite lack of statistical significance. Use of tocolytic drugs was strongly associated with malocclusion risk (OR: 135, 95% CI: 21.0-872), whereas firstborn delivery exhibited a much weaker association (OR: 3.71, 95% CI: 1.03-13.4). Birth by cesarean delivery (OR: 0.446) and same position of fetus during last two months of pregnancy (OR: 0.225) seemed to be slightly protective against malocclusion risk, although the lack of association was not significant. Conclusion: Risk of childhood malocclusion is very strongly associated withprolonged use of beta tocolyticsduring pregnancy. Our study sheds light on the impact of various perinatal risk factors on occurrence of the fetal stomatognathic alterations that ultimately result in malocclusion during childhood
Uncovering mortality patterns and hospital effects in COVID-19 heart failure patients: a novel multilevel logistic cluster-weighted modeling approach
No full textEvaluating hospital performance and its relationship to patients’ characteristics is of utmost importance to ensure timely, effective, and optimal treatment. This is particularly relevant in areas and situations where the healthcare system must deal with an unexpected surge in hospitalizations, such as heart failure patients in the Lombardy Region of Italy during the COVID-19 pandemic. Motivated by this issue, the paper introduces a novel multilevel logistic cluster-weighted model for predicting 45-day mortality following hospitalization due to COVID-19. The methodology flexibly accommodates dependence patterns among continuous and dichotomous variables; effectively accounting for group-specific effects in distinct subgroups showing different attributes. A tailored classification expectation-maximization algorithm is developed for parameter estimation, and extensive simulation studies are conducted to evaluate its performance against competing models. The novel approach is applied to administrative data from the Lombardy Region, with the aim of profiling heart failure patients hospitalized for COVID-19 and investigating the hospital-level impact on their overall mortality. A scenario analysis demonstrates the model’s efficacy in managing multiple sources of heterogeneity, thereby yielding promising results in aiding healthcare providers and policymakers in the identification of patient-specific treatment pathways
Electromyographic evaluation in children orthodontically treated for skeletal Class II malocclusion: Comparison of two treatment techniques
No full textObjective: To compare the clinical efficacy of two techniques for fabricating a Bimler device by assessing the patientâs surface electromyography (sEMG) activity at rest before treatment and six months after treatment. Methods: Twenty-four patients undergoing orthodontic treatment were enrolled in the study; 12 formed the test group and wore a Bimler device fabricated with a Myoprint impression using neuromuscular orthodontic technique and 12 formed the control group and were treated by traditional orthodontic technique with a wax bite in protrusion. The ârestâ sEMG of each patient was recorded prior to treatment and six months after treatment. Results: The neuromuscular-designed Bimler device was more comfortable and provided better treatment results than the traditional Bimler device. Conclusion: This study suggests that the patient group subjected to neuromuscular orthodontic treatment had a treatment outcome with more relaxed masticatory muscles and better function versus the traditional orthodontic treatment
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