When applied to survival data from a population of cancer patients, the log-normal model provides estimates of three important parameters: cured fraction, mean log survival time, and standard deviation log survival time. In the original model, however, these parameters are unrelated to prognostic covariates. Furthermore, the original algorithm is computationally unstable and highly dependent on initial parameter estimates. We have developed an extension of the log-normal model that stabilizes computation and expresses survival parameters as functions of prognostic covariates. We have also developed an ancillary algorithm that provides reliable initial estimates.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1006/cbmr.1994.1014 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Culture-based diversity of endophytic fungi of three species of grown in Iran.
Front Microbiol
May 2024
Division of Biotechnology, Department of Agronomy and Plant Breeding, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
A total of 1,348 endophytic fungal strains were isolated from , , and . They included (16 species), (11 species), (1 species), (2 species), (6 species), (31 species), (7 species), (2 species), and (1 species). had the richest species composition of endophytic fungi, and the endophytic fungi were most abundant in their roots compared to shoots.
View Article and Find Full Text PDFJoint modeling of action sequences and action time in computer-based interactive tasks.
Behav Res Methods
August 2024
Human Development and Quantitative Methodology, University of Maryland, College Park, MD, USA.
Process data refers to data recorded in computer-based assessments that reflect the problem-solving processes of participants and provide greater insight into how they solve problems. Action time, namely the amount of time required to complete a state transition, is also included in such data along with actions. In this study, an action-level joint model of action sequences and action time is proposed, in which the sequential response model (SRM) is used as the measurement model for action sequences, and a new log-normal action time model is proposed as the measurement model for action time.
View Article and Find Full Text PDFAcceptance sampling plans for the three-parameter inverted Topp-Leone model.
Math Biosci Eng
September 2022
Department of Basic Sciences, Obour High Institute for Management & Information, Egypt.
The quadratic rank transmutation map is used in this article to suggest a novel extension of the power inverted Topp-Leone distribution. The newly generated distribution is known as the transmuted power inverted Topp-Leone (TPITL) distribution. The power inverted Topp-Leone and the inverted Topp-Leone are included in the recommended distribution as specific models.
View Article and Find Full Text PDFThe effect of pressure variation on droplet size distribution of dispersed oil under simulated deep-water conditions.
Heliyon
March 2021
Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada.
Droplet size distribution of dispersed oil in deep-water is critical to the transport and biodegradation of spilled oil in deep-sea. Few studies have focused on the effects of pressure on chemically dispersed oil through experiments. This study thus simulated how the crude oil homogenously pre-dispersed by Corexit 9500A using baffled flasks would behave after being exposed to deep-water conditions.
View Article and Find Full Text PDFFrequency distribution of foliar nickel is bimodal in the ultramafic flora of Kinabalu Park (Sabah, Malaysia).
Ann Bot
October 2020
Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Australia.
Background And Aims: The aim of this study was to test the frequency distributions of foliar elements from a large dataset from Kinabalu Park (Sabah, Malaysia) for departure from unimodality, indicative of a distinct ecophysiological response associated with hyperaccumulation.
Methods: We collected foliar samples (n = 1533) comprising 90 families, 198 genera and 495 plant species from ultramafic soils, further foliar samples (n = 177) comprising 45 families, 80 genera and 120 species from non-ultramafic soils and corresponding soil samples (n = 393 from ultramafic soils and n = 66 from non-ultramafic soils) from Kinabalu Park (Sabah, Malaysia). The data were geographically (Kinabalu Park) and edaphically (ultramafic soils) constrained.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!