Statistics

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Circular or directional outcomes are natural responses in many clinical trials (e.g. orthopedics, ophthalmology, sports medicine). Traditionally, clinical trials use equal allocation throughout the trial without utilizing the information contained in the sequentially observed responses in the running trial. Adaptive allocation designs are data-dependent alternatives to assign a greater number of subjects to the better performing treatments using the available data of the running trial in a convenient way. However, adaptive designs for circular responses are rare and, therefore, in the current work, we develop a multi-treatment response-adaptive randomization for circular treatment outcomes considering both the ethics and efficiency requirements. Apart from assessing the proposed allocation design empirically, the applicability of the design in real clinical trials is also enumerated from a practitioner’s viewpoint. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

World University root node

Springer Proceedings in Business and Economics

An Optimal Response-Adaptive Design for Multi-treatment Clinical Trials with Circular Responses

Advances in Statistics-Theory and Applications

Model-Based Clustering for Cylindrical Data

The paper considers a periodic review inventory model for items having deterioration time distributed as two-parameter Weibull. The inventory manager is offered progressive trade credit whereby if the manager pays his dues within the first credit period, he does not have to pay any interest. However, he is charged an interest on the unpaid balance if he pays in the second credit period and the interest is increased if he pays beyond that period. The model is analyzed using the discounted-cash-flow approach, and the optimal stock height and cycle length are determined so as to minimize the present value of all future cash out-flows. Numerical examples are cited, and a sensitivity analysis is carried out to study how robust the model is to change in the parameter values. © 2020, Thai Statistical Association. All rights reserved.

Thailand Statistician

A periodic review inventory model for weibull deteriorating items under trade credit offer using discounted cash-flow approach

arXiv preprint arXiv:2007.

Bias corrected estimators for proportion of true null hypotheses under exponential model: Application of adaptive FDR-controlling in segmented failure data

A multi-arm response-adaptive allocation design is developed for circular treatment outcomes. Several exact and asymptotic properties of the design are studied. Stage-wise treatment selection procedures based on the proposed response-adaptive design are also suggested to exclude the worse performing treatment(s) at earlier stages. Detailed simulation study is carried out to evaluate the proposed selection procedures. The applicability of the proposed methodologies is illustrated through a real clinical trial data on cataract surgery. © 2019 The Korean Statistical Society

GENERAL

Journal of the Korean Statistical Society

Multi-arm response-adaptive designs for circular responses

A class of adaptive designs is formulated in two stages for clinical trials to favour the better performing treatment for further allocation in an efficient way. The first stage of the allocation consists in randomizing subjects to each treatment arm with equal probability and performing a test of equality of treatment effects. The resulting p value and the available estimate of a treatment difference measure is used to assign the incoming second stage subjects. Considering binary and normal responses, several exact and asymptotic properties of the proposed allocation are thoroughly examined and compared with the existing allocation designs. © 2018; Austrian Statistical Society, All rights reserved.

Fulltext

Austrian Journal of Statistics

Adaptive allocation designs for normal and binary treatment responses

A two stage randomized design is developed for two treatment clinical trials in which response variables are exponential and the observations are censored by using failure censoring and time censoring in the first and second stages respectively. The censoring time for the second stage is determined from the outcomes of the first stage. An application to testing for the equality of treatment effects is given along with a comparative study with relevant properties. © 2019, Universidad Nacional de Colombia. All rights reserved.

Revista Colombiana de Estadistica

A randomized two stage adaptively censored design with application to testing [Un diseÃ±o aleatorio censurado adaptativo en dos etapas con aplicaciÃ³n]

Weighing the cumulative odds ratios suitably, a two treatment response adaptive design for phase III clinical trial is proposed for ordinal categorical responses. Properties of the proposed design are investigated theoretically as well as empirically. Applicability of the design is further verified using a data pertaining to a real clinical trial with trauma patients, where the responses are observed in an ordinal categorical scale. © 2019, © 2019 International Biometric Society–Chinese Region.

Biostatistics and Epidemiology

A response adaptive design for ordinal categorical responses weighing the cumulative odds ratios

Platelets, one of the most sensitive blood cells, can be activated by a range of external and internal stimuli including physical, chemical, physiological, and/or non-physiological agents. Platelets need to respond promptly during injury to maintain blood hemostasis. The time profile of platelet aggregation is very complex, especially in the presence of the agonist adenosine 5'-diphosphate (ADP), and it is difficult to probe such complexity using traditional linear dose response models. In the present study, we explored functional analysis techniques to characterize the pattern of platelet aggregation over time in response to nanoparticle induced perturbations. This has obviated the need to represent the pattern of aggregation by a single summarymeasure and allowed us to treat the entire aggregation profile over time, as the response. The modeling was performed in a flexible manner, without any imposition of shape restrictions on the curve, allowing smooth platelet aggregation over time. The use of a probabilistic framework not only allowed statistical prediction and inference of the aggregation signatures, but also provided a novel method for the estimation of higher order derivatives of the curve, thereby allowing plausible estimation of the extent and rate of platelet aggregation kinetics over time. In the present study, we focused on the estimated first derivative of the curve, obtained from the platelet optical aggregometric profile over time and used it to discern the underlying kinetics as well as to study the effects of ADP dosage and perturbation with gold nanoparticles. In addition, our method allowed the quantification of the extent of inter-individual signature variations. Our findings indicated several hidden features and showed a mixture of zero and first order kinetics interrupted by a metastable zero order ADP dose dependent process. In addition, we showed that the two first order kinetic constants were ADP dependent. However, we were able to perturb the overall kinetic pattern using gold nanoparticles, which resulted in autocatalytic aggregation with a higher aggregate mass and which facilitated the aggregation rate. © 2019 Bandyopadhyay, Azharuddin, Dasgupta, Ganguli, SenRoy, Patra and Deb.

Frontiers in Bioengineering and Biotechnology

Probing ADP induced aggregation kinetics during platelet-nanoparticle interactions: Functional dynamics analysis to rationalize safety and benefits

A multi-treatment two stage adaptive allocation design is developed for survival responses. Assuming noninformative random censoring, asymptotic p values of relevant tests of equality of treatment effects are used to derive the assignment probability of incoming second stage subjects. Several ethical and inferential criteria of the design are studied, and are compared with those of an existing competitor. Applicability and performance of the proposed design are also illustrated using a data arising from a real clinical trial. © 2018, © 2018 Taylor & Francis Group, LLC.