Choice procedure

Reinforcing effects were determined based on a multiple choice procedure. 

Forced choice procedures do force the subject to use a very liberal criterion. Even if he is absolutely uncertain, he must still give his best guess. With such a procedure the subject really uses all of his resources and as a result the thresholds found with this procedure are usually lower than with a single yes-no method. 

Similar to our previous smdy of training dose effects (Perkins et al. 1996a), generalization testing across the range of intermediate doses (0-20pgkg ) with the two-choice procedure showed a shift to the left in nicotine-appropriate responding... 

The Lewis acid catalyzed process is not applicable to aryl ketones, where ester products have been observed through aryl migration. Furthermore, anchimeric and solvent effects have been noted during oxidation of a 3-carboxy steroidal ketone. a-Oxygenation, although not inhibited, was altered. Despite the frequently disappointing yields the reagent has been widely used, particularly in the steroid field, and remains a useful, if not first choice , procedure. 

Proteins expressed in bacteria lack post-translational modifications such as phosphorylations and glycosylations. If these are crucial for function, expression in eukaryotic cells is a better choice. Procedures for expression of recombinant proteins in baculovirus or vaccinia virus can be found elsewhere.1516... 

Oral detection thresholds were also obtained by an ascending, three-alternative, forced-choice procedure for three saturated fatty acids that varied in chain length, and one long-chain cA-unsaturated fatty acid [2], Although textural cues were not eliminated, stearic acid emulsions in the oral cavity yielded a mean detection threshold near 0.03% w/v [2], Similar threshold results were obtained with and without nasal airflow. In addition, the mean detection threshold for stearic acid in this population was statistically similar to thresholds for caproic, lauric, and linoleic acids. These results suggest that humans can perceive short-, medium- and long-chain fatty acids in the oral cavity with detection thresholds that do not appear to correlate with the length of the fatty acid chain. 

Siegler, R. S. Strategy choice procedures and the development of multiplication skill. Journal of Experimental Psychology General, 117,258-275.1988. 

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