Results 161 to 170 of about 17,240 (299)

How I Investigate Borderline Prolonged aPTT: An Integrated Laboratory Approach to Mixing Studies and Factor Analysis

International Journal of Laboratory Hematology, EarlyView.
ABSTRACT Borderline prolongation of routine clotting assays—particularly the activated partial thromboplastin time (aPTT)—is a common interpretative challenge in laboratory hematology. These reproducible but mildly prolonged results often lie just beyond the upper reference limit and can trigger unnecessary follow‐up, delays, or misinterpretation ...
Nikolaos Androulakis, Eleni Nioti, Antonios Dilintas, Christina Kalpadakis   +3 more
wiley   +1 more source

Unconditional Variance Estimation Under Complex Surveys

International Statistical Review, EarlyView.
Summary The unconditional framework treats the samples and the variables of interest as random variables. This is particularly suitable with analytic inference, when modelling survey data. We show that variance estimation does not involve finite population corrections and joint‐inclusion probabilities, even with large sampling fractions and under ...
Yves G. Berger
wiley   +1 more source

Consistent Model Specification Tests Against Smooth Transition Alternatives [PDF]

In this paper we develop tests of functional form that are consistent against a class of nonlinear "smooth transition" models of the conditional mean. Our method is an extension of the consistent model specification tests developed by Bierens (1990), de ...
Jonathan B. Hill
core  

The Random Power Function for Tests Based on Pivotal Quantities

International Statistical Review, EarlyView.
Summary In clinical trials planning, evaluation of the probability of success of an experiment is of central interest, for instance, in sample size determination. This assessment typically involves analyses of the power function of a test on a parameter of interest, such as a relevant treatment effect.
Fulvio De Santis, Stefania Gubbiotti, Francesco Mariani   +2 more
wiley   +1 more source

Speciation of European bullheads (Cottus spp.): The next problem for taxonomy of northern freshwater fishes

Journal of Fish Biology, EarlyView.
Abstract High morphological and ecological diversity displayed by European bullheads led Freyhof et al. (2005) to describe 15 nominal species. However, the basis for declaring these nominal species is contentious due to a lack of rigorous statistical analysis of morphological variations among populations, limitations in the inferences made from ...
David S. Murray, Vladimír Kováč, David Wright, Gordon H. Copp   +3 more
wiley   +1 more source

Tests regarding parameters of several independent gamma populations [PDF]

Gamma distribution has been used with considerable success in reliability studies and life testing experiments. This distribution assumes various forms as its shape parameter varies which makes it suitable for analyzing a variety of lifetime data.
Ram Tripathi
core  

Cross‐Sectional Studies: Strengths, Limitations, and Methodological Considerations

Journal of Periodontal Research, EarlyView.
Cross‐sectional studies measure variables at a single time point to estimate prevalence and support descriptive epidemiology ‐ characterizing population health, tracking trends via repeated surveys – and for developing and validating screening instruments and diagnostic models.
Sebastian‐Edgar Baumeister, Thomas Kocher, Panos N. Papapanou, Birte Holtfreter, Ryan T. Demmer   +4 more
wiley   +1 more source

Density‐Valued ARMA Models by Spline Mixtures

Journal of Time Series Analysis, EarlyView.
ABSTRACT This paper proposes a novel framework for modeling time series of probability density functions by extending autoregressive moving average (ARMA) models to density‐valued data. The method is based on a transformation approach, wherein each density function on a compact domain [0,1]d$$ {\left[0,1\right]}^d $$ is approximated by a B‐spline ...
Yasumasa Matsuda, Rei Iwafuchi
wiley   +1 more source

Constructing targeted minimum loss/maximum likelihood estimators: a simple illustration to build intuition. [PDF]

Am J Epidemiol
Ross RK, Montoya LM, Goin DE, Díaz I, Renson A.   +4 more
europepmc   +1 more source

Testing Distributional Granger Causality With Entropic Optimal Transport

Journal of Time Series Analysis, EarlyView.
ABSTRACT We develop a novel nonparametric test for Granger causality in distribution based on entropic optimal transport. Unlike classical mean‐based approaches, the proposed method directly compares the full conditional distributions of a response variable with and without the history of a candidate predictor.
Tao Wang
wiley   +1 more source