The reactions of Soviet nursery day-care and boarding-care children to a strange situation.

Compared the behaviors of 16 day-care and 16 boarding-care Soviet children (average age 30.5 mo) in a strange situation. Time-sampled observations focused on the Ss' general affective state and on their approaches to a responsive stranger. Results support the hypothesis that boarded Ss would be more upset by a strange situation than day-care Ss but reveal no differences between the 2 conditions in Ss' willingness to make social contact with the stranger. Findings are discussed in terms of theory on the effects of parent–child separation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of the quasifree charge-exchange reaction for 12C and 54Fe

Serotonin (5-hydroxytryptamine, 5-HT) in blood is stored in platelets and has vascular and platelet stimulating effects when released into plasma. Accurate measurements of 5-HT in plasma are complicated by inadvertent platelet activation causing sampling artifacts and by analytical problems when determining trace levels. We developed an assay for plasma 5-HT based on solid-phase extraction (Sep-Pak C18), aqueous acetylation, pentafluoropropionylation, and negative ion chemical ionization gas chromatography-mass spectrometry. The method was able to recover 5-HT from plasma by > 90% and to quantitate with a precision of 7.5% at a level of 0.5 nmol/l. It was used to define blood sampling and sample handling procedures giving low and consistent values for 5-HT. A good blood sampling technique, adequate platelet stabilization in the test tube, and rapid high speed centrifugation of the blood resulted in low plasma levels of both 5-HT and beta-thromboglobulin (a platelet release product). Using these procedures plasma 5-HT levels in healthy volunteers were found to be 0.77 +/- 0.38 (mean +/- S.D.; range 0.27-1.49) nmol/l (n = 18), which is 4-100-fold lower than previously reported values.