Clinical phenotypes and outcomes in children with multisystem inflammatory syndrome across SARS-CoV-2 variant eras: a multinational study from the 4CE consortium.

Background: Multisystem inflammatory syndrome in children (MIS-C) is a severe complication of SARS-CoV-2 infection. It remains unclear how MIS-C phenotypes vary across SARS-CoV-2 variants. We aimed to investigate clinical characteristics and outcomes of MIS-C across SARS-CoV-2 eras.

Estimating the Efficiency Gain of Covariate-Adjusted Analyses in Future Clinical Trials Using External Data.

We present a framework for using existing external data to identify and estimate the relative efficiency of a covariate-adjusted estimator compared to an unadjusted estimator in a future randomized trial. Under conditions, these relative efficiencies approximate the ratio of sample sizes needed to achieve a desired power. We develop semiparametrically efficient estimators of the relative efficiencies for several treatment effect estimands of interest with either fully or partially observed outcomes, allowing for the application of flexible statistical learning tools to estimate the nuisance functions.

Seasonal Variation in the Diagnosis of Retinoblastoma.

Purpose: To determine the seasonal variation in the diagnosis of retinoblastoma in a global sample of children and to investigate predictors of seasonal trends.

Methods: Data were collected through a global, multicenter, 1-year cross-sectional analysis that included all treatment- naïve retinoblastoma patients presenting to participating centers between January 1, 2017, and December 31, 2017. Due to variations in days per month, data were normalized to a 30-day/month calendar.

Paired serial limiting dilution assays.

Serial limiting dilution (SLD) assays are a widely used tool in many areas of public health research to measure the concentration of target entities. This concentration can be estimated via maximum likelihood. Asymptotic as well as exact inference methods have been proposed for hypothesis testing and confidence interval construction in this one-sample problem.

Estimating the Efficiency Gain of Covariate-Adjusted Analyses in Future Clinical Trials Using External Data.

We present a general framework for using existing data to estimate the efficiency gain from using a covariate-adjusted estimator of a marginal treatment effect in a future randomized trial. We describe conditions under which it is possible to define a mapping from the distribution that generated the existing external data to the relative efficiency of a covariate-adjusted estimator compared to an unadjusted estimator. Under conditions, these relative efficiencies approximate the ratio of sample size needed to achieve a desired power.

The Convex Mixture Distribution: Granger Causality for Categorical Time Series.

We present a framework for learning Granger causality networks for multivariate categorical time series based on the mixture transition distribution (MTD) model. Traditionally, MTD is plagued by a nonconvex objective, non-identifiability, and presence of local optima. To circumvent these problems, we recast inference in the MTD as a convex problem.

[Effects of different landscape patch structure on the diversity of arthropod community in tea plantations].

A field survey with random block design was conducted to study the effects of different landscape patch structure on the arthropod community in tea plantations. In the tea plantations with small woodland (QM) or Acacia confuse (XS) patches, predatory spider had the highest proportion, occupying 62.3% and 69.

[Determination of four polycyclic aromatic hydrocarbons in anthracene oil for toys by high performance liquid chromatography with diode array detection and fluorescence detection].

A method using high performance liquid chromatography with diode array detection coupled with fluorescence detection was applied to determine four polycyclic aromatic hydro carbons in anthracene oil for toys. This method showed good abilities of the baseline separation and high sensitivity under the optimized analytical conditions. The limits of the fluorescence detection were 0.