A New Principle for Measuring Electrical Length and Deviation from Linear Phase
This paper presents a unique way to measure the equivalent electrical length of a network as well as its deviation from linear phase. The measurement technique used is based upon a variable length transmission line simulator, built into the IF-structure of a 1.3 GHz Network Analyzer, but can be applied to higher frequencies. The new method allows to insert much more electrical length than the mechanical line stretchers do, without disturbing the measurement with additional mismatch errors. In addition to a calibrated readout of the equivalent electrical length in meters, the deviations from linear phase of a network can be presented very accurately in a real time swept display.
The Interpretation of Amplitude and Phase Distortion in Terms of Paired Echoes
In picture-transmission systems, such as television and facsimile, the signal transients are noticeably distorted by small amounts of amplitude and phase distortion. There has been developed a simple method of estimating the effects of such distortion from inspection of the amplitude and phase curves. The distortion is regarded as made up of a pattern of echoes, each echo corresponding to a small amount of distortion of both kinds. The separate interpretation of amplitude and phase distortion requires pairs of echoes, those of each pair being equally displaced in time before and after the signal output. This is called the "method of paired echoes." Amplitude distortion corresponds to symmetrical "positive" pairs whereas phase distortion corresponds to skew-symmetrical "negative" pairs. A complete and exact theory is presented on the basis of a small amount of distortion. The method of paired echoes is most useful in the interpretation of phase curves and the determination of the tolerance of phase distortion.
Comparative studies of α-Lactalbumin and lysozyme: Echidna lysozyme
Summaryα-Lactalbumin is a modifier protein for galactosyl transferase in the biosynthesis of lactose and lysozyme catalyses the cleavage of β(1–4) glycosidic linkages. It is now generally believed that α-lactalbumin and lysozyme have diverged from a common ancestor. Comparative studies of these proteins from several species are reported here.The presence of lactose and lactose synthetase activity is shown in mature milk samples from a variety of placental mammals (eutheria) and a pouch bearing mammal (marsupialia). The isolation of the α-lactalbumins involved and their properties are compared.The position is different in the milk samples of monotremes. The α-lactalbumin, lactose and lactose synthetase activity levels in the two platypus samples studied are very low. The levels of lactose and lactose synthetase activity in some echidna(Tachyglossus aculeatus) samples are low, but appreciable in others. No α-lactalbumin is present. The lysozyme activity is appreciable, some samples containing a different lysozyme from that present in others. One of these (designated echidna lysozyme I) is capable of lactose synthetase modifier activity in the presence of bovine “A protein”.The properties of this lysozyme are compared with those of lysozymes and α-lactalbumins from a variety of species and their significance is discussed.