JSR (Special Issue) Vol 55 Number 1 (2021) September 7, 2021September 7, 2021 Publisher An alternative to the product limit method: the multistate approach By M. A. ISLAM Variable selection for longitudinal survey data By L. DUMITRESCU, W. QIAN, and J. N. K. RAO The impact of incomplete data on quantile regression for longitudinal data By A. VERHASSELT, A. J. FL´OREZ, I. VAN KEILEGOM, and G. MOLENBERGHS Model misspecification under the partially linear single index model By G. Y. YI and W. HE A flexible non-parametric procedure for testing cumulative hazards with applications to oncology studies By Y. ZHANG, A. K. ADENIJI, and M.-H. CHEN A Bayesian semiparametric accelerated failure time cure rate model for censored data By S. K. GHOSH and E. KRACHEY Optimizing DTRs via threshold utility analysis on quality adjusted survival By G. S. JOHNSON, A. S. TOPP and A. S. WAHED Probabilistic diffusion magnetic resonance imaging fiber tracking using a directed acyclic graph auto-regressive model for positive definite matrice By Z. LAN, B. J. REICH, and D. BANDYOPADHYAY A flexible GEV link for zero inflated conway Maxwell Poisson regression with a case study on motor vehicle crashes By X. LI and D. K. DEY A multiple imputation method for nonlinear mixed effects models with missing data By X. DONG and L. WU Inference with joint models under misspecified random effects distributions By A. SATTAR and S. K. SINHA Clustering gene expression time series data embedded in a nonparametric setup By M. KHETAN, S. PAREEK, S. MUKHOPADYAY and K. DAS Analysis of regression discontinuity designs using censored data By Y. CHO, C. HU, and D. GHOSH Sequential and robust data selection in active learning for classification By X. XU and C. SHAY COVID-19 prediction in South Africa: Estimating the unascertained cases – the hidden part of the epidemiological iceberg By X. GU, B. MUKHERJEE, S. DAS, and J. DATTA