Cross-sectional area (CSA) is a fundamental variable in characterizing muscle mechanical properties. Typically, the CSA of a single muscle fibre is assessed by measuring either one or two diameters, and assuming the cross-section is either circular or elliptical in shape. However, fibre cross-sections have irregular shapes. The accuracy and precision of CSAs determined using circular and elliptical shape assumptions are unclear for mammalian skinned muscle fibres. Second harmonic generation imaging of skinned rabbit soleus fibres revealed that the circular assumption overstated real CSA by 5.3±25.9% whereas the elliptical assumption overstated real CSA by 2.8±6.9%. A preferred rotational alignment can bias the circular assumption, as real CSA was overstated by 22.1±24.8% when using the larger fibre diameter and understated by 11.4±13% when using the smaller fibre diameter. With 73% lower variable error and reduced bias, the elliptical assumption is superior to the circular assumption when assessing the CSA of skinned mammalian fibres.
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http://dx.doi.org/10.1242/jeb.248187 | DOI Listing |
J Appl Crystallogr
January 2024
Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Flow cells are ubiquitous in laboratories and automated instrumentation, and are crucial for ease of sample preparation, analyte addition and buffer exchange. The assumption that the fluids have exchanged completely in a flow cell is often critical to data interpretation. This article describes the buoyancy effects on the exchange of fluids with differing densities or viscosities in thin, circular flow cells.
View Article and Find Full Text PDFBiol Rev Camb Philos Soc
November 2024
U.S. Geological Survey, Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844, USA.
Mechanisms governing the migratory decisions of birds have long fascinated ecologists and sparked considerable debate. Identifying factors responsible for variation in migration distance, also known as differential migration, has been a popular approach to understanding the mechanisms underlying migratory behaviour more generally. However, research progress has been slowed by the continued testing of overlapping, non-mechanistic, and circular predictions among a small set of historically entrenched hypotheses.
View Article and Find Full Text PDFSci Rep
November 2024
School of Civil Engineering, University of Science and Technology Liaoning, No. 189 Qianshan Middle Road, Lishan District, Anshan City, 114051, Liaoning Province, People's Republic of China.
Connection method of lengthening the steel tube of circular hollow sandwich concrete-filled steel tube by inside lining tube and thread is proposed. Twelve circular hollow sandwich concrete filled steel tubular beam-column connected by thread through inside lining tube are designed and fabricated using the length of the thread along the axial direction, the working height of the thread, and the position of the thread as parameters; In addition, one unconnected specimen and two welded specimens also are designed and fabricated to conduct controlled experimental research. The test phenomena and failure modes, axial compressive load-compression curve, axial compressive load-lateral deflection curve, and axial compressive load-strain in steel tube curve, as well as bearing capacity, strength reservation, deflection curve shape, lateral stiffness, ductility and plane section assumption are analyzed.
View Article and Find Full Text PDFJ Clin Neurosci
December 2024
Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge University Hospitals, Cambridge, UK.
Pathogens
October 2024
Department of Medical Microbiology and Infectious Diseases, University of Manitoba, 745 Bannatyne Ave., Winnipeg, MB R3E 0J9, Canada.
is an underdiagnosed and underreported etiology of pneumonia. serogroup 1 (LpSG1) is thought to be the most common pathogenic subgroup. This assumption is based on the frequent use of a urinary antigen test (UAT), only capable of diagnosing LpSG1.
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