Odor psychophysics and sensory engineering

This paper illustrates the utilization of psychophysical scalingand optimization technology to accomplish two goals. First,by means of ‘goal programming’ the odor scientistcan interrelate chemicals and odor qualities, specify a desiredprofile of odor qualities and determine that combination ofodorants which come as close as possible to generating thatdesired profile. Second, by means of non-linear optimization,the scientist can determine the relation between chemical concentrationsand liking, and furthermore ascertain that combination of chemicalconcentrations which generate maximal liking ratings, subjectto constraints. Constraints include chemical concentrationslying within prespecified limits, and sensory perceptions lyingwithin specific bounds. Mixtures of butyric acid and pulegoneillustrate the approach.     

Purification and characterization of chick intestine brush border membrane Effects of 1α(OH) vitamin D3 treatment

A new technique has been developed for the isolation of membrane vesicles from the vitamin D-deficient and vitamin D-treated chick intestinal brush border membrane. The technique involves removal of nuclei from a low speed pellet by discontinuous sucrose gradient centrifugation. The resulting intact brush borders are then homogenized in 0.5 M Tris and the membrane fragments purified on a glycerol gradient. This preparation represents a 20-fold purification of the brush border marker sucrase. After 1α-hydroxyvitamin D₃ treatment there is a significant increase in membrane phospholipid phosphorous, an alteration in the fatty acid composition of the phosphatidylcholine fraction of membrane phospholipid, and a decrease in sucrase specific activity.     

Fine structure of frozen-etched lipid granules in the fat body of an insect

Lipid storage in fat-body cells of adult female black flies was examined using freeze-etching electron microscopy. Frozen-etched lipid granules exhibited a laminated structure. The molecular arrangement of the lipid granule may depend on the physiological condition of the insect and may be involved in the control of lipid metabolism in the fat-body cell.     

Effect of Disodium Cromoglycate on Exercise-induced Asthma

In eight patients with exercise-induced asthma, disodium cromoglycate was found to produce a definite inhibition of the post-exercise fall in forced expiratory volume in one second. This effect may be part of the cause for the subjective improvement experienced with this drug.     

Conditional Maximum Likelihood Estimation Following a Group Sequential Test

We consider estimation after a group sequential test. An estimator that is unbiased or has small bias may have substantial conditional bias (Troendle and Yu, 1999, Coburger and Wassmer, 2001). In this paper we derive the conditional maximum likelihood estimators of both the primary parameter and a secondary parameter, and investigate their properties within a conditional inference framework. The method applies to both the usual and adaptive group sequential test designs. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)