ABSTRACT
Solid-state imagers offer a variety of options to the modern optical microscopist. Photodiode arrays, charge injection devices, and charge-coupled devices are the three basic types of solid-state imagers available for research imaging. The charge-coupled device (CCD) is the solid-state imager of choice, because of its superior characteristics and its widespread acceptance in the research environment. The performance characteristics of the CCD are well documented and understood, having been quantified by many experimenters, especially in the physical sciences. CCDs exhibit dynamic ranges up to 50,000:1, very high quantum efficiency, and ultralow noise. The camera system in which a device is used, however, dictates the overall performance which can be achieved. The CCD imaging system as it applies to cell biology is discussed in detail in Hiraoka et al. (1987). A video camera operating at 30 frames/second does not provide the resolution, low noise, dynamic range, and linearity of a slow scan, cooled camera operating at 1 frame/second. Conversely, a slow scan camera does not offer the user the facility to resolve rapidly changing events in real time. The analogy between an 8-mm movie camera (video camera) and a 35-mm snapshot camera (slow scan cooled camera) is a useful one to emphasize the different character of these two electronic imaging systems. These two basic camera systems both employ CCD imagers, and each has very different, but complementary, characteristics. No one camera system can address the wide variety of imaging problems which face the modern microscopist. The user of this new generation of instrumentation must decide which system best fits the problem at hand.
Subject(s)
Microscopy/instrumentation , Silicon , Calibration , Crystallography , Light , Optics and Photonics , Photography/instrumentation , TelevisionABSTRACT
Photovoltaic indium antimonide detectors have been operated at temperatures
Subject(s)
Infant, Premature , Metabolism , Homeostasis , Humans , Infant Nutritional Physiological Phenomena , Infant, NewbornABSTRACT
Two balance studies were performed on each of five infants of low birth weight. About 230 ml/kg/day of S.M.A. S26 milk was given during one study and 180 ml/kg/day during the other. The proportion of nitrogen, fat, and calories retained was similar in the two studies, suggesting that the larger weight gains on the high-volume feeds were due to growth rather than retention of water or excessive deposition of fat.
