Water induced soil erosion leads to a loss in soil productivity. It is a widely recognized problem and there is a public desire to induce farmer behavior that will prevent or control soil erosion. Farmers are largely motivated by economic considerations and, rather than control erosion per se, may adopt land-saving technology that compensates for soil productivity losses due to erosion. Collective action to implement soil conservation policy is often required when private landowner interests diverge from society’s interests. Erosion prevention or control enforcement, cost sharing, technical assistance, education, tax incentives and credit subsidies represent some policy instruments that may be used. However, enabling legislation pursuant to establishment of soil conservation districts provides an important institutional arrangement to further decentralize decision making with respect to erosion prevention and control, to supplement existing policies and programs and to provide flexibility in dealing with particular attributes of local erosion problems.

The dynathermal current and capacitance responses of two isotopes of sulfur, 32s and 34s predeposited by low fluence ion implantation into siliconp +- n junction diodes are presented. As opposed to all previous studies, in this work unequal densities are seen for the shallow and deep sulfur defects, for both the 32s− and 34− related defects. Additionally, the dynathermal response of the deep 34s center is seen to exhibit a shift of 3 K from that of 32S at a fixed heating rate of 9.5 ±0.1 K/s, consistent with the isotope dependence of the thermal emission process observed earlier for these cen-ters by isothermal capacitance measurements.

Two energy levels of sulfur in the upper half of the energy gap of silicon were obtained by isothermal transient capacitance and thermally stimulated current measurements on samples prepared by sulfur implantation and high-temperature annealing. The measured energy levels are in good agreement with two levels for sulfur introduced by a closed-tube diffusion but disagree with one of two levels measured for implanted sulfur after low-temperature annealing.

THE vitamin A of mammalian sera appears to be present principally as the alcohol, whereas the vitamin A of the liver is present mainly in ester form. As regards avian species, Neff et al.1 have shown that the vitamin A of hen's egg yolk is present largely as the alcohol. Parrish et al.2 have shown that the alcohol of the yolk is transformed in part to ester during incubation, and that the ester is the principal form in the livers of newly hatched chicks.

This paper describes a highspeed telemetering system which uses frequency as a translating means. Equipment for two different frequency bands of 20 to 25 cycles and 80 to 100 cycles has been developed. The system is electronic and the lag between a change in the primary quantity to a change in the receiver is less than 0.4 second. The system is independent of the wave shape and amplitude of the signal over extremely wide limits. Means are provided for automatic calibration at frequent intervals which compensate for changes in vacuum tubes and other circuit elements.