Utilization Of Nitrogen Sources By Immature Soybean Cotyledons In Culture

Immature Glycine max (L.) Merrill cotyledons were cultured in a defined medium containing different nitrogen sources. Glutamine was the most efficient source in terms of protein accumulation in the cotyledons. Asparagine was less efficient (about 70 per cent that of glutamine) while allantoin was a poor source of nitrogen. This was also true for older cotyledons where asparaginase and allantoinase activities were maximal. The utilization of both asparagine and allantoin (but not glutamine) was totally inhibited by methionine sulfoximine suggesting that their metabolism involves ammonia assimilation via glutamine synthetase. Apparently, neither exogenous or endogenously-generated ammonia had much effect on glutamine utilization, but ammonia did have a small inhibitory effect on asparagine, which may in part account for the lower efficiency observed with this amide. © 1987 Annals of Botany Company.59659760

DIRECTIVITY AND SENSITIVITY OF HIGH FREQUENCY CARRIER TYPE THIN-FILM MAGNETIC FIELD SENSOR

We discuss the directivity and sensitivity of high frequency carrier type thin-film magnetic sensor (or so-calledMI sensor.) The inductance of the sensor changes as a function of the angle, θ, between the appliedmagnetic field, Hdc, direction and the length direction of the sensor. The relationbetween the inductance and the angle is cos3θ because the inductance varies as Hdc3. The effective magnetic fieldinside the magnetic thin-film is proportional to Hdc cosθ because of the rectangular shape. Moreover, the highsensitivity of 2 x 10-4 Oe has been demonstrated provided a 140 MHz carrier current and lock-in amplifierdetection