Background And Objectives: Doubts have been raised concerning the validity of the 20-m shuttle-run test (20 mSRT) as a predictor of cardiorespiratory fitness (CRF) in youth based on Léger's equation/model. An alternative allometric model has been published recently that is thought to provide, not only a superior fit (criterion validity) but also a more biologically and physiologically interpretable model (construct validity). The purposes of this study were to explore whether allometry can provide a more valid predictor of CRF using 20 mSRT compared with Léger's equation/model.
Methods: We fitted and compared Léger's original model and an alternative allometric model using two cross-sectional datasets (youth, n = 306; adult n = 105) that contained measurements of CRF ([Formula: see text]/[Formula: see text]) and 20 mSRT performance. Quality-of-fit was assessed using explained variance (R) and Bland and Altman's limits of agreement.
Results: The allometric models provided superior fits for the youth (explained variance R = 71.9%) and adult (R = 77.7%) datasets compared with Léger's equation using their original fixed (R = 35.2%) or re-estimated parameter models (R = 65.9%), confirming that the allometric models demonstrate acceptable criterion validity. However, the allometric models also identified a non-linear "J-shaped" increase in energy cost ([Formula: see text]/[Formula: see text]) with faster final shuttle-run speeds (fitted speed exponent = 1.52; 95% CI 1.38-1.65).
Conclusion: Not only do allometric models provide more accurate predictions of CRF ([Formula: see text]/[Formula: see text]; ml kg min) for both youth and adults (evidence of criterion validity), the "J-shaped" rise in energy demand with increasing final shuttle-run speed also provides the evidence of construct validity, resulting in a more plausible, physiologically sound, and interpretable model.
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http://dx.doi.org/10.1007/s40279-020-01346-0 | DOI Listing |
Antibodies (Basel)
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Eli Lilly and Company, Lilly Corporate Center Indianapolis, Indianapolis, IN 46285, USA.
Background: The prediction of human clearance (CL) and subcutaneous (SC) bioavailability is a critical aspect of monoclonal antibody (mAb) selection for clinical development. While monkeys are a well-accepted model for predicting human CL, other preclinical species have been less-thoroughly explored. Unlike CL, predicting the bioavailability of SC administered mAbs in humans remains challenging as contributing factors are not well understood, and preclinical models have not been systematically evaluated.
View Article and Find Full Text PDFPeerJ
January 2025
Department of Zoology, University of Tartu, Tartu, Estonia.
Body size has always been the focus of several ecological studies due to its undeniable influence on other life-history traits. The conventional representation of body size in arthropods typically relies on linear measures, such as total body length, or the length of specific body parts that can be used to represent body size. While these measures offer simplicity over more complicated alternatives (.
View Article and Find Full Text PDFExpert Rev Clin Pharmacol
January 2025
Department of Medical Cosmetology, Hunan Provincial Hospital of Maternal and Child Health Care.
Background: Anrikefon (HSK21542), a potent and selective peripheral kappa opioid receptor (KOR) agonist developed by Haisco, effectively blocks pain and itch signals.
Aim: To develop a population pharmacokinetic (PK) model for anrikefon and conduct exposure-response (E-R) analysis for safety and efficacy in postoperative pain patients.
Method: The Population PK analysis uses NONMEM software with data from six trials.
Vet Med Sci
January 2025
Department of Animal Breeding and Husbandry, Istanbul University-Cerrahpasa, Istanbul, Türkiye.
Background: Obtaining information about the growth rates of animals' organs and tissues can help understand their meat production potential and determine the ideal slaughter weight (SW).
Objectives: This study aimed to determine the effects of production system and SW on the allometric growth of the non-carcass components, carcass cuts, and hind limb tissues of Kivircik lambs.
Methods: A total of 54 single-born male lambs were randomly allocated into production systems (concentrate- and pasture-based) and SW groups: 25-26 kg (LOW), 30-31 kg (MEDIUM), and 35-36 kg (HIGH).
Epilepsia
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Unit of Innovative Treatments, Hospital de Pediatría JP Garrahan, Buenos Aires, Argentina.
Objective: Identifying factors influencing cannabidiol (CBD) exposure can optimize treatment efficacy and safety. We aimed to describe the population pharmacokinetics of CBD in children with drug-resistant developmental and epileptic encephalopathies (DEEs) and assess the influence of environmental, pharmacological, and clinical characteristics on CBD systemic exposure.
Methods: Data from two pharmacokinetic studies of patients aged 2-18 years with DEEs were included (N = 48 patients).
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