Calcium imaging a single wavelength or two wavelengths expressed as a ratio (ratiometric indicators). The derived fluorescence intensities and ratios are plotted against calibrated values for known Ca levels to learn Ca concentration. Light field microscopy methods extend functional readout of neural activity capabilities in 3D volumes. Calcium imaging Calcium imaging is a scientific technique usually carried out in research which is designed to show the calcium (Ca) status of an isolated cell, tissue or medium. Calcium imaging techniques take advantage of so-called calcium indicators, fluorescent molecules that can respond to the binding of Ca ions by changing their fluorescence properties. Two
What If?: Serious Scientific Answers to Absurd Hypothetical Questions What If?: Serious Scientific Answers to Absurd Hypothetical Questions What If?: Serious Scientific Answers to Absurd Hypothetical Questions is a non-fiction book by Randall Munroe in which the author answers hypothetical science questions sent to him by readers of his webcomic, "xkcd". The book contains a selection of questions and answers originally published on his blog "What If?", along with several new ones. The book is divided into several dozen chapters, most of which are devoted to answering a unique question. "What If?" was released in September 2, 2014 and was received positively by critics. In the introduction section of