3,214 research outputs found
An acoustical hypothesis for the spiral bubble nets of humpback whales and the implications for whale feeding
Ten Little Fingers And Ten Little Toes (Down In Tennessee)
https://digitalcommons.library.umaine.edu/mmb-vp/6226/thumbnail.jp
Evidence of a Pro-Arrhythmic Substrate in the Failing Right Ventricle of Pulmonary Hypertensive Rats
The role of transient outward K+ current in electrical remodelling induced by voluntary exercise in female rat hearts
Regular exercise can lead to electrical remodelling of the heart. The cellular mechanisms associated with these changes are not well understood, and are difficult to study in human tissue but are important given that exercise is recommended to the general population. We have investigated the role played by the transient outward K+ current (Ito) in the changes in electrical activity seen in response to voluntary exercise training in rats. Female rats undertook 6Â weeks of voluntary wheel running exercise (TRN) or were sedentary controls (SED). Monophasic action potentials (MAPs) were recorded from the surface of whole hearts. Whole cell patch clamp recordings of Ito; mRNA and protein levels of selected targets in sub-epicardial (EPI) and sub-endocardial myocardium of SED and TRN hearts were compared. In TRN rats, heart weight:body weight was significantly increased and epicardial MAPs significantly prolonged. Ito density was reduced in TRN EPI myocytes, such that the transmural gradient of Ito was significantly reduced (PÂ <Â 0.05). Computer modelling of these changes in Ito predicted the observed changes in action potential profile. However, transmural gradients in mRNA and protein expression for Kv4.2 or mRNA levels of the Kv4.2 regulators; KChIP2 and Irx-5 were not significantly altered by voluntary exercise. We conclude that voluntary exercise electrical remodelling is caused, at least in part, by a decrease in EPI Ito, possibly because of fewer functional channels in the membrane, which results in a fall in the transmural action potential duration gradient
A 1987 progress report of manufacturing techniques for Gravity Probe B gyroscope rotors
The significant improvements in the manufacture of Gravity Probe B gyroscope rotors developed since the publication of the last report on this project are presented. The improvements include the polishing machine structure, rough laps, finishing/polishing laps, lapping procedure, measurement techniques, and a summary of the manufacturing status. These six areas represent significant improvements in the manufacture of the gyroscope rotors to meet flight requirements
Two stages of parafoveal processing during reading: Evidence from a display change detection task
We used a display change detection paradigm (Slattery, Angele, & Rayner Human Perception and Performance, 37, 1924â1938 2011) to investigate whether display change detection uses orthographic regularity and whether detection is affected by the processing difficulty of the word preceding the boundary that triggers the display change. Subjects were significantly more sensitive to display changes when the change was from a nonwordlike preview than when the change was from a wordlike preview, but the preview benefit effect on the target word was not affected by whether the preview was wordlike or nonwordlike. Additionally, we did not find any influence of preboundary word frequency on display change detection performance. Our results suggest that display change detection and lexical processing do not use the same cognitive mechanisms. We propose that parafoveal processing takes place in two stages: an early, orthography-based, preattentional stage, and a late, attention-dependent lexical access stage
Tidal Creeks as Sentinel Habitats: A Conceptual Model for Describing the Effects of Land Use Change on Coastal Ecosystems
2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio
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