G(ST) and its relatives are often interpreted as measures of differentiation between subpopulations, with values near zero supposedly indicating low differentiation. However, G(ST) necessarily approaches zero when gene diversity is high, even if subpopulations are completely differentiated, and it is not monotonic with increasing differentiation. Likewise, when diversity is equated with heterozygosity, standard similarity measures formed by taking the ratio of mean within-subpopulation diversity to total diversity necessarily approach unity when diversity is high, even if the subpopulations are completely dissimilar (no shared alleles). None of these measures can be interpreted as measures of differentiation or similarity. The derivations of these measures contain two subtle misconceptions which cause their paradoxical behaviours. Conclusions about population differentiation, gene flow, relatedness, and conservation priority will often be wrong when based on these fixation indices or similarity measures. These are not statistical issues; the problems persist even when true population frequencies are used in the calculations. Recent advances in the mathematics of diversity identify the misconceptions, and yield mathematically consistent descriptive measures of population structure which eliminate the paradoxes produced by standard measures. These measures can be directly related to the migration and mutation rates of the finite-island model.
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http://dx.doi.org/10.1111/j.1365-294x.2008.03887.x | DOI Listing |
Biomed Phys Eng Express
January 2025
Mindanao Radiation Physics Center, MSU-Iligan Institute of Technology, Andres Bonifacio Street Tibanga, Iligan City, Lanao Norte, 9200, PHILIPPINES.
To accurately model and validate the 6 MV Elekta Compactlinear accelerator using the Geant4 Application for Tomographic Emission (GATE). In particular, this study focuses on the precise calibration and validation of critical parameters, including jaw collimator positioning, electron source nominal energy, flattening filter geometry, and electron source spot size, which are often not provided in technical documentation. Methods: Simulation of the Elekta Compact6 MV linear accelerator was performed using the Geant4 Application for Tomographic Emission (GATE) v.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
Xi'an Jiaotong University, No.28 Xianning West Road, Xi'an, Shaanxi 710049, P.R. China, Xi'an, 710049, CHINA.
The optimal method for three-dimensional thermal imaging within cells involves collecting intracellular temperature responses while simultaneously obtaining corresponding 3D positional information. Current temperature measurement techniques based on the photothermal properties of quantum dots face several limitations, including high cytotoxicity and low fluorescence quantum yields. These issues affect the normal metabolic processes of tumor cells.
View Article and Find Full Text PDFJMIR Form Res
December 2024
Department of Communication, Stanford University, Stanford, US.
Background: Contrary to popular concerns about the harmful effects of media use on mental health, research on this relationship is ambiguous, stalling advances in theory, interventions, and policy. Scientific explorations of the relationship between media and mental health have mostly found null or small associations, with the results often blamed on the use of cross-sectional study designs or imprecise measures of media use and mental health.
Objective: This exploratory empirical demonstration aimed to answer whether mental health effects are associated with media use experiences by (1) redirecting research investments to granular and intensive longitudinal recordings of digital experiences to build models of media use and mental health for single individuals over the course of one entire year, (2) using new metrics of fragmented media use to propose explanations of mental health effects that will advance person-specific theorizing in media psychology, and (3) identifying combinations of media behaviors and mental health symptoms that may be more useful for studying media effects than single measures of dosage and affect or assessments of clinical symptoms related to specific disorders.
J Strength Cond Res
December 2024
Jayhawk Athletic Performance Laboratory, Wu Tsai Human Performance Alliance, University of Kansas, Lawrence, Kansas.
Eserhaut, DA, DeLeo, JM, and Fry, AC. Blood flow restricted resistance exercise in well-trained men: Salivary biomarker responses and oxygen saturation kinetics. J Strength Cond Res 38(12): e716-e726, 2024-Resistance exercise with continuous lower-limb blood flow restriction (BFR) may provide supplementary benefit to highly resistance-trained men.
View Article and Find Full Text PDFJ Strength Cond Res
December 2024
Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, Mississippi; and.
Hammert, WB, Dankel, SJ, Kataoka, R, Yamada, Y, Kassiano, W, Song, JS, and Loenneke, JP. Methodological considerations when studying resistance-trained populations: Ideas for using control groups. J Strength Cond Res 38(12): 2164-2171, 2024-The applicability of training effects from experimental research depends on the ability to quantify the degree of measurement error accurately over time, which can be accounted for by including a time-matched nonexercise control group.
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