Confidence Intervals for the Overlapping Coefficient: the Normal Equal Variance Case

Moving Forward to a World Beyond 0.2, 0.5, and 0.8 Effects Sizes: New Cutoffs for School-Based Anti-Bullying Interventions

Effect sizes of school-based intervention are commonly described as small to moderate when using Cohen's conventional effect size cutoffs (small [0.2], medium [0.5], and large [0.8]). However, Jacob Cohen's rule of thumb might vary across different areas of research, nature of the intervention, and population, because effect sizes are context-dependent. Moreover, when planning research studies, minimum detectable effect sizes are used to calculate the sample size. In the present study, we investigate whether conventional effect size cutoffs (small [0.2], medium [0.5], and large [0.8]) represent the reported distribution of effect sizes in school-based anti-bullying intervention. To determine small, medium, and large effect sizes, we calculated the effect size distribution (ESD) using 50th percentile effect size (medium effect) of the distributions of effect sizes provided by a recent meta-analysis on school-based anti-bullying intervention. Also, the 25th and 75th percentile effects, as they are equidistant from the average effect size, were used redefining small and large effects, respectively. Results showed that 0.07, 0.123, and 0.227 represent small, medium, and large effect sizes in anti-bullying interventions. Our results indicate that Cohen's suggested effect size thresholds (0.2, 0.5, and 0.8) overestimate effect sizes when compared to the real-world context of school based anti-bullying interventions. We also propose sample sizes required to reliably detect small, medium, and large percentile effect sizes in anti-bullying interventions.

Forecasting outcomes after cholecystectomy in octogenarian patients

BACKGROUND

Although gallstone disease increases with aging, elderly patients are less likely to undergo cholecystectomy. This is because age itself is a negative predictor after cholecystectomy. The ACS-NSQIP risk calculator can therefore help surgeons decide whether to operate or not. However, little is known about the accuracy of this model outside the ACS National Surgical Quality Improvement Program. The aim of the present study is to evaluate the ability of the ACS-NSQIP model to predict the clinical outcomes of patients aged 80 years or older undergoing elective or emergency cholecystectomy.

STUDY DESIGN

The study focused on 263 patients over 80 years of age operated on between 2010 and 2019: 174 were treated as emergencies because of acute cholecystitis (66.2%). Outcomes evaluated are those predicted by the ACS-NSQIP calculator within 30 days of surgery. The ACS-NSQIP model was tested for both discrimination and calibration. Differences among observed and expected outcomes were evaluated.

RESULTS

When considering all patients, the discrimination of mortality was very high, as it was that of severe complications. Considering only the elective cholecystectomies, the discrimination capacity of ACS-NSQIP risk calculator has consistently worsened in each outcome while it remains high considering the emergency cholecystectomies. In the evaluation of the emergency cholecystectomy, the model showed a very high discriminatory ability and, more importantly, it showed an excellent calibration. Comparisons between main outcomes showed small or even negligible differences between observed and expected values.

CONCLUSION

The results of the present study suggest that clinical decisions on cholecystectomy in a patient aged 80 years or older should be assisted through the ACS-NSQIP model.

Inference on the overlap coefficient: The binormal approach and alternatives

The overlap coefficient (OVL) measures the similarity between two distributions through the overlapping area of their distribution functions. Given its intuitive description and ease of visual representation by the straightforward depiction of the amount of overlap between the two corresponding histograms based on samples of measurements from each one of the two distributions, the development of accurate methods for confidence interval construction can be useful for applied researchers. The overlap coefficient has received scant attention in the literature since it lacks readily available software for its implementation, while inferential procedures that can cover the whole range of distributional scenarios for the two underlying distributions are missing. Such methods, both parametric and non-parametric are developed in this article, while R-code is provided for their implementation. Parametric approaches based on the binormal model show better performance and are appropriate for use in a wide range of distributional scenarios. Methods are assessed through a large simulation study and are illustrated using a dataset from a study on human immunodeficiency virus-related cognitive function assessment.

CogTale: an online platform for the evaluation, synthesis, and dissemination of evidence from cognitive interventions studies

Systematic reviews and meta-analyses are critical in health-related decision-making, and are considered the gold standard in research synthesis methods. However, with new trials being regularly published and with the development of increasingly rigorous standards of data synthesis, systematic reviews often require much expertise and long periods of time to be completed. Automation of some of the steps of evidence synthesis productions is a promising improvement in the field, capable of reducing the time and costs associated with the process.This article describes the development and main characteristics of a novel online repository of cognitive intervention studies entitled Cognitive Treatments Article Library and Evaluation (CogTale). The platform is currently in a Beta Release phase, as it is still under development. However, it already contains over 70 studies, and the CogTale team is continuously coding and uploading new studies into the repository. Key features include advanced search options, the capability to generate meta-analyses, and an up-to-date display of relevant published studies.

Swim Program Pilot for Children with Autism: Impact on Behaviors and Health

The purpose of this mixed methods pre-/post-pilot intervention study was to assess parental psychological health and child challenging behaviors before and after a swimming program for children with autism. Participants were 10 parent-child dyads. Child's challenging behaviors were lower in the post testing (Cohen's d = 0.07-0.45). Mean scores were improved for parent perception of general health (Cohen's d = 0.22). Three themes emerged from the post swim program focus group: (a) Parent satisfaction with instructors with sub themes (i) firmness (ii) creativity, and (iii) promotion of social interaction and sharing, (b) improved child sleeping, and (c) family dynamics with sub themes (i) siblings wanted to swim and (ii) parents' fear of drowning. Preliminary results point to improved child behaviors and parent perception of general health. Future studies can focus on expanding the swim program to include all family members.

Plant susceptibility to ozone: A tower of Babel?

In a world with climate change and environmental pollution, modern Biology is concerned with organismic susceptibility. At the same time, policy and decision makers seek information about organismic susceptibility. Therefore, information about organismic susceptibility may have far-reaching implications to the entire biosphere that can extend to several forthcoming generations. Here, we review a sample of approximately 200 published peer-reviewed articles dealing with plant response to ground-level ozone to understand how the information about susceptibility is communicated. A fuzzy and often incorrect terminology was used to describe the responsiveness of plants to ozone. Susceptibility was classified too arbitrarily and this was reflected to the approximately 50 descriptive words that were used to characterize susceptibility. The classification of susceptibility was commonly based on calculated probability (p) value. This practice is inappropriate as p values do not provide any basis for effect or susceptibility magnitude. To bridge the gap between science and policy decision making, classification of susceptibility should be done using alternative approaches, such as effect size estimates in conjunction with multivariate ordination statistics.

Enzyme activity modification in adult beetles (Agelastica coerulea) inhabiting birch trees in an ozone-enriched atmosphere

Tropospheric ozone (O₃) is a naturally occurring gas in the atmosphere. However, the concentration of O₃ increased in the twentieth century. Although the effects of O₃ on vegetation have been extensively studied since the 1950s, limited information exists regarding the effects of O₃ on insect herbivores. In particular, evidence is lacking regarding the effects of O₃ on the biology of insect herbivores. Agelastica coerulea Baly (1874) is a coleopteran species that grazes on Betulaceae plants. In this study, to investigate the effects of O₃ on A. coerulea biology for the first time, female adult insects were collected from Japanese white birch trees grown in a Free Air Controlled Exposure System (FACE) in Sapporo, Japan. These beetles inhabited trees exposed either to ambient or to elevated O₃ for 23 days. After collection, the enzyme activities in the beetles were measured. Elevated O₃ led to a greater total antioxidant activity and lower α- and β-esterase activities, a phenomenon that may suggest an increased resistance of the beetles to stress. Our results are further discussed with regard to biological and toxicological aspects. Collectively, our findings indicate that total antioxidants and α- and β-esterase activities can serve as effective O₃ biomarker systems in this beetle species. This adaptive response of the beetle, which was induced by moderate O₃ exposure, should be further tested across generations and for its protection against greater exposure.

Variability in the Results of Meta-Analysis as a Function of Comparing Effect Sizes Based on Scores From Noncomparable Measures: A Simulation Study

Meta-analysis is a significant methodological advance that is increasingly important in research synthesis. Fundamental to meta-analysis is the presumption that effect sizes, such as the standardized mean difference (SMD), based on scores from different measures are comparable. It has been argued that population observed score SMDs based on scores from different measures A and B will be equal only if the conjunction of three conditions are met: construct equivalence (CE), equal reliabilities (ER), and the absence of differential test functioning (DTF) in all subpopulations of the combined populations of interest. It has also been speculated the results of a meta-analysis of SMDs might differ between circumstances in which the SMDs included in a meta-analysis are based on measures which all met the conjunction of these conditions and that in which the conjunction of these conditions is violated. No previous studies have tested this conjecture. This Monte Carlo study investigated this hypothesis. A population of studies comparing one of five hypothetical treatments with a placebo condition was simulated. The SMDs in these simulated studies were based on true scores from six hypothetical measures. The scores from some of these measures met the conjunction of CE, ER, and, the absence of DTF, while others failed to meet CE. Three meta-analyses were conducted using both fixed effects and random effects methods. The results suggested that the results of meta-analyses can vary to a practically significant degree when the SMDs were based on scores from measures failing to meet the CE condition. Implications for future research are considered.

Diagnostic Accuracy of 3.0-T Magnetic Resonance T1 and T2 Mapping and T2-Weighted Dark-Blood Imaging for the Infarct-Related Coronary Artery in Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

Patients with recent non-ST-segment elevation myocardial infarction commonly have heterogeneous characteristics that may be challenging to assess clinically.

METHODS AND RESULTS

We prospectively studied the diagnostic accuracy of 2 novel (T1, T2 mapping) and 1 established (T2-weighted short tau inversion recovery [T2W-STIR]) magnetic resonance imaging methods for imaging the ischemic area at risk and myocardial salvage in 73 patients with non-ST-segment elevation myocardial infarction (mean age 57±10 years, 78% male) at 3.0-T magnetic resonance imaging within 6.5±3.5 days of invasive management. The infarct-related territory was identified independently using a combination of angiographic, ECG, and clinical findings. The presence and extent of infarction was assessed with late gadolinium enhancement imaging (gadobutrol, 0.1 mmol/kg). The extent of acutely injured myocardium was independently assessed with native T1, T2, and T2W-STIR methods. The mean infarct size was 5.9±8.0% of left ventricular mass. The infarct zone T1 and T2 times were 1323±68 and 57±5 ms, respectively. The diagnostic accuracies of T1 and T2 mapping for identification of the infarct-related artery were similar (P=0.125), and both were superior to T2W-STIR (P<0.001). The extent of myocardial injury (percentage of left ventricular volume) estimated with T1 (15.8±10.6%) and T2 maps (16.0±11.8%) was similar (P=0.838) and moderately well correlated (r=0.82, P<0.001). Mean extent of acute injury estimated with T2W-STIR (7.8±11.6%) was lower than that estimated with T1 (P<0.001) or T2 maps (P<0.001).

CONCLUSIONS

In patients with non-ST-segment elevation myocardial infarction, T1 and T2 magnetic resonance imaging mapping have higher diagnostic performance than T2W-STIR for identifying the infarct-related artery. Compared with conventional STIR, T1 and T2 maps have superior value to inform diagnosis and revascularization planning in non-ST-segment elevation myocardial infarction.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02073422.

Stem and crown growth of Japanese larch and its hybrid F1 grown in two soils and exposed to two free-air O3 regimes

Ozone (O₃) pollution and soil infertility may negatively affect boreal forests across the Northern Hemisphere. Impacts to economically and ecologically important larches (Larix sp., Pinacaeae) are particularly concerning. Using a free air O₃ enrichment (FACE) system, we investigated the effect of 2-year elevated O₃ exposure (≈66 nmol mol^-1) on Japanese larch (L. kaempferi) and its hybrid larch F₁ (L. gmelinii var. japonica × L. kaempferi) planted directly into either fertile brown forest soil (BF) or BF mixed with infertile volcanic ash soil (VA). Overall, photosynthetic pigmentation and the growth performance of the stem and crown were reduced in both taxa exposed to elevated O₃. Furthermore, hybrid larch, in both O₃ treatments, performed better than Japanese larch. This finding contradicts findings of prior experiments with potential experimental artifacts of O₃ exposure facilities and root restrictions. Elevated O₃ also disproportionately inhibited stem diameter growth and caused an imbalance in chlorophylls a/b and chlorophyll/carotenoid ratios. Hybrid and Japanese larches grown in BF and VA had a significantly lower drop of stem diameter over the run of stem height (from base to top) when exposed to elevated O₃, compared to ambient O₃. This finding indicates altered stem shape under elevated O₃. Among 11 response variables, there were no significant interactions between O₃ treatment and taxa. There was also no significant interaction of soil condition and taxa, suggesting that the two larches shared a similar response to O₃ and soil type. Understanding the performance of hybrid larch in relation to its parent species has ramifications for breeding success in a soil-degraded and O₃-polluted environment.

Effect of the Crystal Environment on Side-Chain Conformational Dynamics in Cyanovirin-N Investigated through Crystal and Solution Molecular Dynamics Simulations

Side chains in protein crystal structures are essential for understanding biochemical processes such as catalysis and molecular recognition. However, crystal packing could influence side-chain conformation and dynamics, thus complicating functional interpretations of available experimental structures. Here we investigate the effect of crystal packing on side-chain conformational dynamics with crystal and solution molecular dynamics simulations using Cyanovirin-N as a model system. Side-chain ensembles for solvent-exposed residues obtained from simulation largely reflect the conformations observed in the X-ray structure. This agreement is most striking for crystal-contacting residues during crystal simulation. Given the high level of correspondence between our simulations and the X-ray data, we compare side-chain ensembles in solution and crystal simulations. We observe large decreases in conformational entropy in the crystal for several long, polar and contacting residues on the protein surface. Such cases agree well with the average loss in conformational entropy per residue upon protein folding and are accompanied by a change in side-chain conformation. This finding supports the application of surface engineering to facilitate crystallization. Our simulation-based approach demonstrated here with Cyanovirin-N establishes a framework for quantitatively comparing side-chain ensembles in solution and in the crystal across a larger set of proteins to elucidate the effect of the crystal environment on protein conformations.

Inhibition requirements of the human apical sodium-dependent bile acid transporter (hASBT) using aminopiperidine conjugates of glutamyl-bile acids

PURPOSE

Synthesize aminopiperidine conjugates of glutamyl-bile acids (glu-BAs) and develop a hASBT inhibition model using the conformationally sampled pharmacophore (CSP) approach.

METHODS

glu-BAs aminopiperidine conjugates were synthesized. hASBT inhibition was measured as K(i). A CSP-SAR model was built using structural and physico-chemical descriptors and evaluated via cross-validation.

RESULTS

Twenty-nine aminopiperidine conjugates were synthesized. All inhibited hASBT, with K(i) ranging from 0.95 to 31.8 muM. Amidation of the piperidine nitrogen slightly decreased activity, while replacement by a carbon increased potency. Esterification of the glutamic acid linker had a minor impact, suggesting that a negative charge around C-24 is not required for binding. Three quantitative CSP-SAR models were developed. The best model (r (2) = 0.813, Q (2) = 0.726) included two descriptors: angle between 7-OH, alpha-substituent and centroid of rings B and C, and electrostatic contribution to the solvation free-energy. The model successfully distinguished between compounds with K(i) < 16muM and K(i) > 16muM. Models indicated that hydrophobicity, alpha substituent orientation, and partially compacted side chain conformation promote inhibitory potency. Qualitative CSP-SAR analysis indicated that the presence of an internal salt bridge, resulting in a locked conformation of the side chain, yielded weaker inhibitors.

CONCLUSIONS

Aminopiperidine conjugates of glu-BAs were potent hASBT inhibitors. A predictive and robust CSP-SAR model was developed.