Spontaneous alternation behavior in humans: Implications for psychological research.

It is suggested that 1 response-influencing variable in psychological experiments may be the individual S's need for sensory variation as manifested in alternation behavior. The proposition is put forth that in an experimental situation where a discriminatory response to one of a series of successively presented stimuli is required, the organism will seek to optimize the amount of stimulus variability or complexity by alternation behavior. (32 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biosynthesis and structure of glycosyl diglycerides,steryl glucosides,and acylated steryl glucosides

A particulate enzyme fraction from Mycobacterim smegmatis catalyzed the transfer of -14C-glucose from the UDP--14C-glucose into neutral glycolipids. The two major radioactive components were purified by column chromatography on O-diethylamino ethyl cellulose (acetate) and thin layer chromatography on silica gel in several solvents. The first product yielded a water-soluble component upon saponification, which had a hexoseglycerol ratio of 1:1 with all of the hexose being identified as glucose. The second product yielded a water-soluble component upon saponification which contained hexose and glycerol in a 2:1 ratio and, in addition to glucose, contained lesser amounts of mannose and galactose. Palmitate and oleate were the predominant fatty acids and were present in equimolar amounts. The products thus have been identified as monoglycosyldiglyceride and diglycosyldiglyceride. The diglycosyldiglyceride could also be labeled with -14C-galactose when UDP--14C-galactose served as the donor, but the monoglycosyldiglyceride was only slightly labeled with -14C-galactose. Membrane fractions from mung bean seedlings catalyzed the transfer of -14C-glucose from UDP--14C-glucose into a neutral glycolipid which has been purified by thin layer chromatography and analyzed by combined gas liquid chromatography-mass spectrometry. It was determined to be a steryl glucoside with the two major sterol components being betasitosterol and stigmasterol linked to beta-D-glucose. Particulate fractions from developing cotton fibers also catalyzed the formation of steryl glucosides and, in addition, they catalyzed the esterification of steryl glucosides at the 6 position of glucose with fatty acids (primarily palmitate and oleate) from an andogenous acyl donor. Both the glucosyl transferase and the acyltransferase have been solubilized with Triton X-100 and partially purified by chromatography on Sephadex G-200. The acyltransferase activity was reconstituted by the addition of the steryl glucoside and a phospholipid acyl donor.     

On seed proteins Part 11. Purification,Chemical Composition,and Some Physico-chemical Properties of the 11 S Globulin (Helianthinin) in Sunflower Seed

An improved procedure for the isolation and purification of the 11 S globulin from sunflower seeds (helianthinin) is described, including a combined purification by gel chromatography and ionexchange chromatography. The protein has a sedimentation constant of s_{20, w} = 12.8 x 10^?13 s, a Stokes radius of 57 Å and a diffusion constant of 3.76 x 10^?7 cm² s^?1 (the last two derived from gel chromatographic analysis). Hence it follows a molecular weight of M_{s, D} = 305000. The isoelectric point determined by isoelectric focusing lies at pH 4.7. High contents of glutamic (26%) and aspartic (14%) acid and arginine (9.7%) as well as a low content of sulphur containing amino acids are characteristic for the amino acid composition. 59% of the acidic amino acids are present in an amidated form. The globulin contains 12 disulphide bridges per molecule.     

Smoke reduction for flexible PVC-high surface area: Alumina trihydrate vs. magnesium hydroxide

This paper reviews three flexible PVC formulations using various types of alumina trihydrate (ATH) and magnesium hydroxide [Mg(OH)₂]. Smoke values are compared. In two of the formulations, Mg(OH)₂ has better smoke values than ATH; in a third formulation, ATH has better smoke values than Mg(OH)₂. However, the third formulation uses an ATH with a very high surface area, which may indicate that smoke suppression may be a function of not only the type of flame retardants used but also surface area.     

A membrane-permeant, bioactivatable derivative of Ins(1,3,4)P3 and its effect on Cl(-)-secretion from T84 cells

The synthesis of rac-2,5,6-tri-O-butyryl-myo-inositol 1,3,4-trisphosphate hexakis(acetoxymethyl) ester [Bt3-Ins(1,3,4)P3/AM, 1], a membrane-permeant derivative of myo-inositol 1,3,4-trisphosphate [Ins(1,3,4)P3] is reported. 1 inhibited calcium-mediated chloride secretion of T84 cells, suggesting a regulatory link of Ins(1,3,4)P3 and the biosynthesis of the known inhibitor myo-inositol 3,4,5,6-tetrakisphosphate.