MRI-derived Articular Cartilage Strains Predict Patient-Reported Outcomes Six Months Post Anterior Cruciate Ligament Reconstruction.

Key terms: Multicontrast and Multiparametric, Magnetic Resonance Imaging, Osteoarthritis, Functional Biomechanical Imaging, Knee Joint Degeneration What is known about the subject: dualMRI has been used to quantify strains in a healthy human population in vivo and in cartilage explant models. Previously, OA severity, as determined by histology, has been positively correlated to increased shear and transverse strains in cartilage explants. What this study adds to existing knowledge: This is the first in vivo use of dualMRI in a participant demographic post-ACL reconstruction and at risk for developing osteoarthritis. This study shows that dualMRI-derived strains are more significantly correlated with patient-reported outcomes than any MRI relaxometry metric. Background: Anterior cruciate ligament (ACL) injuries lead to an increased risk of osteoarthritis, characterized by altered cartilage tissue structure and function. Displacements under applied loading by magnetic resonance imaging (dualMRI) is a novel MRI technique that can be used to quantify mechanical strain in cartilage while undergoing a physiological load. Purpose: To determine if strains derived by dualMRI and relaxometry measures correlate with patient-reported outcomes at six months post unilateral ACL reconstruction. Study Design: Cohort study. Methods: Quantitative MRI (T2, T2*, T1ρ) measurements and transverse, axial, and shear strains were quantified in the medial articular tibiofemoral cartilage of 35 participants at six-months post unilateral ACL reconstruction. The relationships between patient-reported outcomes (WOMAC, KOOS, MARS) and all qMRI relaxation times were quantified using general linear mixed-effects models. A combined best-fit multicontrast MRI model was then developed using backwards regression to determine the patient features and MRI metrics that are most predictive of patient-reported outcome scores. Results: Higher femoral strains were significantly correlated with worse patient-reported functional outcomes. Femoral shear and transverse strains were positively correlated with six-month KOOS and WOMAC scores, after controlling for covariates. No relaxometry measures were correlated with patient-reported outcome scores. We identified the best-fit model for predicting WOMAC score using multiple MRI measures and patient-specific information, including sex, age, graft type, femoral transverse strain, femoral axial strain, and femoral shear strain. The best-fit model significantly predicted WOMAC score (p<0.001) better than any one individual MRI metric alone. When we regressed the model-predicted WOMAC scores against the patient-reported WOMAC scores, we found that our model achieved a goodness of fit exceeding 0.52. Conclusions: This work presents the first use of dualMRI in vivo in a cohort of participants at risk for developing osteoarthritis. Our results indicate that both shear and transverse strains are highly correlated with patient-reported outcome severity could serve as novel imaging biomarkers to predict the development of osteoarthritis.

Interventions to counter misinformation: Lessons from the Global North and applications to the Global South.

We synthesize evidence from 176 experimental estimates of 11 interventions intended to combat misinformation in the Global North and Global South, which we classify as informational, educational, sociopsychological, or institutional. Among these, we find the most consistent positive evidence for two informational interventions in both Global North and Global South contexts: inoculation/prebunking and debunking. In a complementary survey of 138 misinformation scholars and practitioners, we find that experts tend to be most optimistic about interventions that have been least widely studied or that have been shown to be mostly ineffective. We provide a searchable database of misinformation randomized controlled trials and suggest avenues for future research to close the gap between expert opinion and academic research.

Anti-elite attitudes and support for independent candidates.

The ideological dispute between left and right has dominated the political discussion for decades in multiple countries across the globe. However, in recent years people vs. elite debates have replaced traditional ideological conflicts in explaining voters' electoral decisions. In this paper, we investigate whether anti-elite attitudes contribute to a key political outcome: the increase in successful independent candidates. We implement a conjoint experiment in Chile, where anti-elite sentiments and the number of successful independent politicians are currently prominent. We find that preferences for independent candidates largely increase among voters with anti-elite orientations. In a context where traditional parties face difficult times, such beliefs are key to understanding the factors behind support for candidates with no party affiliation. This insight is important because electing independent politicians can promote a personalistic style of politics, undermine democratic accountability, and foster conflict between the executive and legislative branches.

The shot, the message, and the messenger: COVID-19 vaccine acceptance in Latin America.

Herd immunity by mass vaccination offers the potential to substantially limit the continuing spread of COVID-19, but high levels of vaccine hesitancy threaten this goal. In a cross-country analysis of vaccine hesitant respondents across Latin America in January 2021, we experimentally tested how five features of mass vaccination campaigns-the vaccine's producer, efficacy, endorser, distributor, and current population uptake rate-shifted willingness to take a COVID-19 vaccine. We find that citizens preferred Western-produced vaccines, but were highly influenced by factual information about vaccine efficacy. Vaccine hesitant individuals were more responsive to vaccine messengers with medical expertise than political, religious, or media elite endorsements. Citizen trust in foreign governments, domestic leaders, and state institutions moderated the effects of the campaign features on vaccine acceptance. These findings can help inform the design of unfolding mass inoculation campaigns.