Outer hair cells amplify and improve the frequency selectivity of sound within the mammalian cochlea through a sound-evoked receptor potential that induces an electromechanical response in their lateral wall membrane. We experimentally show that the membrane area and linear membrane capacitance of outer hair cells increases exponentially with the electrically evoked voltage-dependent charge movement (Q(T)) and peak membrane capacitance (C(peak)). We determine the size of the different functional regions (e.g., lateral wall, synaptic basal pole) of the polarized cells from the tonotopic relationships. We then establish that Q(T) and C(peak) increase with the logarithm of the lateral wall area (A(LW)) and determine from the functions that the charge (σ(LW,) pC/μm(2)) and peak (ρ(LW,) pF/μm(2)) densities vary inversely with A(LW) (σ(LW) = 1.3/A(LW) and ρ(LW) = 9/A(LW)). This shows contrary to conventional wisdom that σ(LW) and ρ(LW) are not constant along the length of an individual outer hair cell.
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http://dx.doi.org/10.1016/j.bpj.2012.04.054 | DOI Listing |
Plants (Basel)
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Department of Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341, Republic of Korea.
Morphophysiological dormancy (MPD) is considered one of the most primitive dormancy classes among seed plants. While extensive studies have examined the occurrence of endo-β-mannanase in seeds with physiological dormancy (PD) or non-dormancy, little is known about the activity of this enzyme in seeds with MPD. This study aimed to investigate the temporal and spatial patterns of endo-β-mannanase activity during dormancy break and germination.
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Department of Plastic and Reconstructive Surgery, Chonnam National University Hospital, Chonnam National University Medical School, 42 Jebong-ro, Dong-gu, Gwangju 61469, Republic of Korea.
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MSA ENT Academy Centre, Via T. Piano, 16, 03043 Cassino, FR, Italy.
: The video head impulse test is a landmark in vestibular diagnostic methods to assess the high-frequency semicircular canal system. This test is well established in the adult population with immense research since its discovery. The usefulness and feasibility of the test in children is not very well defined, as research has been limited.
View Article and Find Full Text PDFBMC Oral Health
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Department of Otorhinolaryngology - Head and Neck Surgery, Turku University Hospital and University of Turku, Savitehtaankatu 5, Turku, 20520, Finland.
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Respir Med Res
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Department of Respiratory and Sleep Medicine, Angers University hospital, Angers, France; MitoVasc, Carme, SFR ICAT, CNRS 6015, Inserm 1083, University of Angers, Angers, France. Electronic address:
Introduction: Non-invasive ventilation (NIV) is the reference treatment for chronic respiratory failure (CRF) due to impairment of the ventilatory system. Home initiation is increasingly practiced. To better support this ambulatory shift, we aimed to assess the implementation constraints and short-term efficacy according to different aetiologies of CRF.
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