In real-world scenes, the different objects and events are often interconnected within a rich web of semantic relationships. These semantic links help parse information efficiently and make sense of the sensory environment. It has been shown that, during goal-directed search, hearing the characteristic sound of an everyday life object helps finding the affiliate objects in artificial visual search arrays as well as in naturalistic, real-life videoclips.
View Article and Find Full Text PDFMolecular motors such as kinesin and myosin often work in groups to generate the directed movements and forces critical for many biological processes. Although much is known about how individual motors generate force and movement, surprisingly, little is known about the mechanisms underlying the macroscopic mechanics generated by multiple motors. For example, the observation that a saturating number, N, of myosin heads move an actin filament at a rate that is influenced by actin-myosin attachment and detachment kinetics is accounted for neither experimentally nor theoretically.
View Article and Find Full Text PDFEarly identification of treatment needs in incarcerated individuals with serious mental illness has significant implications. Validated assessment instruments to guide treatment are lacking in correctional settings. Hierarchical linear modeling was used to examine the predictive validity of the Level of Care Index (LOCI) in 35 inmates admitted to a specialized treatment unit.
View Article and Find Full Text PDFObjectives: In the absence of a reliable biomarker, clinical decisions for a functional gastrointestinal (GI) disorder like irritable bowel syndrome (IBS) depend on asking patients to appraise and communicate their health status. Self-ratings of health (SRH) have proven a powerful and consistent predictor of health outcomes, but little is known about how they relate to those relevant to IBS (e.g.
View Article and Find Full Text PDFTo determine the mechanism by which sucrose slows in vitro actin sliding velocities, V, we used stopped flow kinetics and a single molecule binding assay, SiMBA. We observed that in the absence of ATP, sucrose (880mM) slowed the rate of actin-myosin (A-M) strong binding by 71±8% with a smaller inhibitory effect observed on spontaneous rigor dissociation (21±3%). Similarly, in the presence of ATP, sucrose slowed strong binding associated with Pi release by 85±9% with a smaller inhibitory effect on ATP-induced A-M dissociation, kT (39±2%).
View Article and Find Full Text PDFIn striated muscle, calcium binding to the thin filament (TF) regulatory complex activates actin-myosin ATPase activity, and actin-myosin kinetics in turn regulates TF activation. However, a quantitative description of the effects of actin-myosin kinetics on the calcium sensitivity (pCa50) and cooperativity (nH) of TF activation is lacking. With the assumption that TF structural transitions and TF-myosin binding transitions are inextricably coupled, we advanced the principles established by Kad et al.
View Article and Find Full Text PDFUnloaded shortening speeds, , of muscle are thought to be limited by actin-bound myosin heads that resist shortening, or = ·· where is the rate at which myosin detaches from actin and is myosin's step size. The -term describes the efficiency of force transmission between myosin heads, and has been shown to become less than one at low myosin densities in a motility assay. Molecules such as inorganic phosphate, P, and blebbistatin inhibit both and actin-myosin strong binding kinetics suggesting a link between and attachment kinetics.
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