This Technical Note presents an overview of the transient overvoltages that can occur on the electricity distribution network, how they are classified, their causes, and how they propagate through the network. Integral Energy, your local Network Operator or the Integral Energy Power Quality and Reliability Centre can give you additional advice if you have particular concerns with these issues. ...

OBJECTIVES To study the time course of Ca2+ transients recorded from the left ventricular epicardial surface of isolated hearts from rabbits with heart failure and to correlate the results with mechanical function. METHODS Heart failure was induced in the rabbit 8 weeks after coronary ligation (n = 17) with 13 controls. Echocardiography was used to assess in vivo left ventricular dysfunction....

Striatal spiny projection neurons control basal ganglia outputs via action potential bursts conveyed to the globus pallidus and substantia nigra. Accordingly, burst activity in these neurons contributes importantly to basal ganglia function and dysfunction. These bursts are driven by multiple corticostriatal inputs that depolarize spiny projection neurons from their resting potential of approxi...

Voltage-gated calcium channels (VGCCs) serve as a critical link between electrical signaling and diverse cellular processes in neurons. We have exploited recent advances in genetically encoded calcium sensors and in culture techniques to investigate how the VGCC alpha1 subunit EGL-19 and alpha2/delta subunit UNC-36 affect the functional properties of C. elegans mechanosensory neurons. Using the...

Amadou, Aı̈ssata, Artur Nawrocki, Martin Best-Belpomme, Catherine Pavoine, and Françoise Pecker. Arachidonic acid mediates dual effect of TNFon Ca2 transients and contraction of adult rat cardiomyocytes. Am J Physiol Cell Physiol 282: C1339–C1347, 2002. First published January 30, 2002; 10.1152/ajpcell.00471.2001.—Tumor necrosis factor (TNF)has a biphasic effect on heart contractility and stimul...

To assess interleukin (IL)-4 effects on calcium signaling, bovine airway smooth-muscle (ASM) cells were loaded with fura-2 and cytosolic calcium ([Ca(2+)](i)) was measured in single cells by digital microscopy. Human recombinant IL-4 (50 ng/ml) caused small increases in [Ca(2+)](i). For single cells, carbachol-stimulated calcium transients were compared before (S1) and after (S2) exposure to IL...

Although ventricular cardiomyocytes express inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] receptors, it is unclear how these Ca2+ channels contribute to the effects of Gq-coupled agonists. Endothelin-1 augmented the amplitude of pacing-evoked Ca2+ signals (positive inotropy), and caused an increasing frequency of spontaneous diastolic Ca2+-release transients. Both effects of endothelin-1 were blo...

During development axon outgrowth and branching are independently regulated such that axons can stall or retract while their interstitial branches extend toward targets. Previous studies have shown that guidance cues and intracellular signaling components can promote branching of cortical axons without affecting axon outgrowth. However, the mechanisms that regulate differential outgrowth of axo...

Primary segmentation of visual scenes is based on spatiotemporal edges that are presumably detected by neurons throughout the visual system. In contrast, the way in which the auditory system decomposes complex auditory scenes is substantially less clear. There is diverse physiological and psychophysical evidence for the sensitivity of the auditory system to amplitude transients, which can be co...

PURPOSE To investigate the effects of arginine vasopressin (AVP) on Ca(2+) sparks and oscillations and on sarcoplasmic reticulum (SR) Ca(2+) content in retinal arteriolar myocytes. METHODS Fluo-4-loaded smooth muscle in intact segments of freshly isolated porcine retinal arteriole was imaged by confocal laser microscopy. SR Ca(2+) store content was assessed by recording caffeine-induced Ca(2+...