Crystal growth of some rare earth trifluorides

Single crystals of GdF₃, TbF₃, DyF₃, HoF₃ and ErF₃ have been grown by using a Bridgman-Stockbarger method utilising sealed platinum crucibles. DyF₃ and HoF₃ have also been grown by the Czochralski technique.     

Seeking urgent pediatric treatment: Factors contributing to frequency, delay, and appropriateness.

Explored the factors that contributed to mothers' decisions to seek urgent medical attention for their children when symptoms were not of a traumatic nature. 89 mothers (mean age 28.4 yrs) seeking treatment for their children (mean age 5.3 yrs) at a prepaid clinic completed a questionnaire eliciting their expectations regarding the course of their children's problems, seriousness of the problems, perceived responsibility for the symptoms, and extent to which a variety of factors contributed to their decisions to seek treatment. Demographic data and information about each child's symptoms and medical history were also obtained. Four major reasons for seeking treatment were identified: family history of the presenting complaint, worry regarding the symptoms, situational variables, and the extent of the child's illness behavior. The appropriateness of the visit, delay in seeking treatment, and frequency of mothers' use of the pediatric clinic were predicted by the nature of the presenting symptoms (particularly the presence of fever), the ages of the mother and child, and 2 of the reasons for seeking treatment factors (i.e., family history, child's illness behavior). It is suggested that mothers should pay more attention to presenting symptoms and to the children's behavior than to psychosocial stressors in deciding to seek urgent care. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A cross-sectional study of emotion recognition in schizophrenics.

48 hospitalized schizophrenics and 48 nonhospitalized normals were administered a test of emotion recognition that included photographs depicting facial expressions of 8 emotions. Ss were then given the Vocabulary test of the Wide Range Achievement Test. The groups were subdivided by age: children (8–22 yrs), adolescents (13–29 yrs), and adults (20–50 yrs). Patients and normals were matched on age, sex, and educational level. Normals were significantly better than schizophrenics at identifying all of the emotions, and this difference held across sex and age groups. Schizophrenics and normals did not differ in the types of errors they made. Findings are discussed in light of theories regarding social and emotional functioning in schizophrenics. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

System identification in the presence of a ramp disturbance

The elimination of the effect of a ramp disturbance in the determination of the impulse-response function of a time-invariant system is described. The system uses a chain-code test signal. It is shown that the error due to the ramp disturbance may be eliminated by careful choice of the commencement of the period, of duration equal to the chain-code period, over which the computation is performed.     

ESTIMATION OF VOLATILE SULPHUR COMPOUNDS IN BEER

A method has been developed for the quantitative estimation of volatile sulphur compounds in beer at levels below 0.1 μg litre^?1. The method relies on the concentration of beer headspace volatiles onto a porous polymer followed by injection into a capillary gas chromatographic column using a thermal desorption cold trap injector. The volatile components are separated using temperature programming and detected by a flame photometric detector specific for sulphur compounds. The mean concentrations and the estimates of r₉₅ (μg litre^?1) for volatile sulphur compounds measured in a commercial lager were respectively: methanethiol (0.33, 0.30); dimethyl sulphide (19.3, 5.3); carbon disulphide (0.42, 0.32); ethylene sulphide (0.37, 0.05); 1-propanethiol (0.11, 0.02); methyl thioacetate (11.7; 2.7); methyl disulphide (0.34, 0.42). The method is a significant improvement over previous techniques for the quantification of sulphur-containing volatiles in beer .     

Acute nicotinic blockade produces cognitive impairment in normal humans

Single oral doses of the central and peripheral nicotinic antagonist mecamylamine were administered to healthy young normal males in doses of 5, 10, and 20 mg in a placebo-controlled, double-blind study. The 20 mg dose caused a significant increase in errors in the learning condition of the Repeated Acquisition task, producing a slower acquisition curve. The lower doses produced less errors, but more than in the placebo condition. There was no effect of drug on the performance component (retrieval of previously learned information). On the recognition memory task, dose-related increases in false-alarms during the delay period were seen, with little effect on misses or hits. Reaction time measures suggested a dose-related slowing of RT on several tasks. Behavioral effects were minimal and physiologic measures were consistent with dose-related ganglionic blockade. We interpret these results to indicate that acute blockade of nicotinic receptor function can produce measurable and significant cognitive impairment, even in non-smoking normals.