Abstract: Brefeldin A derivatives of the formula ##STR1## where R is alkyl, unsubstituted or substituted alkanoyl, unsubstituted or substituted aralkyl, unsubstituted or substituted benzoyl, a radical of the formula (R.sup.1 O).sub.2 P(O)-- or a radical R.sup.2 R.sup.3 R.sup.4 Si, and the use of brefeldin A and brefeldin A derivatives of the formula I for combatting unwanted plant growth.

Abstract: Monitoring device for densitometrically evaluating printed sheets with a printed print-monitoring strip includes holding means, a plurality of first densitometers for exclusively measuring full-tone density carried by the holding means at a selective spacing from one another so as to define respective gaps between the first densitometers, and a plurality of second densitometers for measuring at least one tone density value selected from a range of screen and full tone values, the second densitometers being receivable, respectively, in the gaps between the first densitometers and being connectible to a device for mathematically correlating the values measured by the second densitometers with quality-assessing parameters.

Abstract: One piece ribbon spool molded from suitable plastic, with no fastening hardware with spool or on ribbon required, comprising spaced circular side guide flanges, a central cylindrical hub joined by radial ribs with ribbon-receiving segmental cylindrical wall, a female ribbon latch forming a hook for receiving free end of a male ribbon latch to anchor end of ribbon therebetween, other end of male latch forming unitary hinge connection, and outer surfaces of latches when in ribbon-anchoring position describing extension of cylindrical surface of segmental ribbon-receiving wall, the male latch being narrower than the space separating the side flanges, and apertures in the latter opposite the latches to facilitate engagement and disengagement of the ribbon and the spool.