Soybean metal-binding proteins: calmodulin purification by hydrophobic interaction with polymer 3520.

Polymer 3520, a non-polar styrene divinylbenzene polymer, provides a simple way to purify calmodulin (CAM) from soybeans. This polymer, which selectively adsorbs CAM by hydrophobic interaction within the polymer matrix, contains no exchangeable groups; thus, interaction with CAM requires no Ca++ ions, and elution is achieved with 50% ethanol. Purification by this form of reversed-phase liquid chromatography is a substantial improvement over the conventional method, which requires high salt in elution buffers. CAM in soybean meal is first extracted with 80% ethanol in the presence of EGTA at room temperature and then chromatographed directly on a polymer 3520 column to yield pure CAM. Addition of non-ionic detergent (Nonidet P-40) to the ethanolic extract helps to separate extraneous proteins, lipids, sugars, and isoflavones. Such isolated CAM migrates as a single band during polyacrylamide gel electrophoresis and reversed-phase HPLC, and it retains activity stimulatory to phosphodiesterase.

Videothermometry for assay of fescue foot in cattle.

Surface temperatures of hoofs of calves given toxic anion fractions of tall fescue were measured with an infrared sensitive camera. These changes expressed in terms of a weighted average coronary band temperature relate to clinical signs of fescue foot. The weighted average coronary band temperature values for control calves given saline solution were 27 to 31 C; those values of test calves given anion fractions of tall fescue were as low as 22 +/- 1 C. Videothermometry provides an independent, permanent, objective measure that is useful in assessing fescue-foot potential of tall fescue fractions by intraperitoneal injection. Videothermometry may also serve as a clinical means for determining progression of the total fescue foot syndrome.

Temperature-based Prediction of egg-mass production by Meloidogyne incognita.

A maturation-rate relationship for Meloidogyne incognita on Lycopersicon esculentum 'Rutgers' was derived and used to estimate harvest dates for maximum egg hatch from laboratory cultures at ambient temperatures. Daily maturation increments were totaled (nematode maturation total, NMT) and correlated with hatch from isolated white, yellow, and amber egg masses. Hatch per mass fluctuated periodically from ca. 1.0 NMT, when egg masses were first visible, to 2.5 NMT by which time plants showed stress. Maximum yields from white and yellow masses occurred, with a shorter than expected periodicity, at 1.5-1.8 and 2.1-2.2 NMT. White masses decreased from 90% of the total masses at 1.0 NMT to 5% at 2.5 NMT, as the proportion of yellow and amber masses increased concomitantly. Harvested masses per gram of root varied from 97 to 276; hatch per gram of root, 11,000 to 86,000.