Likelihood-Based Inference for Semi-Parametric Transformation Cure Models with Interval Censored Data

A simple yet effective way of modeling survival data with cure fraction is by considering Box-Cox transformation cure model (BCTM) that unifies mixture and promotion time cure models. In this article, we numerically study the statistical properties of the BCTM when applied to interval censored data. Time-to-events associated with susceptible subjects are modeled through proportional hazards structure that allows for non-homogeneity across subjects, where the baseline hazard function is estimated by distribution-free piecewise linear function with varied degrees of non-parametricity. Due to missing cured statuses for right censored subjects, maximum likelihood estimates of model parameters are obtained by developing an expectation-maximization (EM) algorithm. Under the EM framework, the conditional expectation of the complete data log-likelihood function is maximized by considering all parameters (including the Box-Cox transformation parameter $\alpha$) simultaneously, in contrast to conventional profile-likelihood technique of estimating $\alpha$. The robustness and accuracy of the model and estimation method are established through a detailed simulation study under various parameter settings, and an analysis of real-life data obtained from a smoking cessation study.Comment: 20 page

Study of aquatic biodiversity and correlation with physical parameters of Jalangi river

The present study is concerned to assess the present status of aquatic biodiversity and its correlation with few physical parameters of river Jalangi. The study shows more than 35 species of freshwater fishes, eight species of zooplanktons, four species of dragonflies and two species of damselflies, few species of mollusks, which reflects that the river Janangi is full of diversity with respect to flora and fauna. The river is full of eel grass. River Jalangi is also a habitat of water striders, few crab species and aquatic snakes. In few areas, pollution may affect the present ecological status of Jalangi River in near future. This preliminary study identifies the overall biodiversity status of Jalangi. However, more work in this direction is required to make complete database on floral and faunal diversity of this river. DOI: http://dx.doi.org/10.5281/zenodo.451652

An overview of floral and faunal diversity in and around Barrackpore Rastraguru Surendranath College Campuses, West Bengal, India

The present survey based study involves the qualitative diversity of flora and fauna. The diversity assessment was carried out at two campuses of Barrackpore Rastraguru Surendranath College. This extensive study reveals the presence of 256 floral species and 165 faunal species in and around college campuses. The huge faunal diversity is mainly due to high level of floral diversity, which establishes the area as resource-rich habitat with promising reservoir of species. This is the very first effort in exploring the natural wealth of Barrackpore Rastraguru Surendranath College campuses. DOI: http://dx.doi.org/10.5281/zenodo.369591

Disformal transformations and the motion of a particle in semi-classical gravity

The approach to incorporate quantum effects in gravity by replacing free particle geodesics with Bohmian non-geodesic trajectories has an equivalent description in terms of a conformally related geometry, where the motion is force free, with the quantum effects inside the conformal factor, i.e., in the geometry itself. For more general disformal transformations relating gravitational and physical geometries, we show how to establish this equivalence by taking the quantum effects inside the disformal degrees of freedom. We also show how one can solve the usual problems associated with the conformal version, namely the wrong continuity equation, indefiniteness of the quantum mass, and wrong description of massless particles in the singularity resolution argument, by using appropriate disformal transformations.Comment: 18 Pages, LaTe