A quantitative comparison of taste reactivity behaviors to sucrose before and after lithium chloride pairings: A unidimensional account of palatability.

Alterations in the motivation to ingest sucrose can be quantified by measuring the number and type of oral motor and somatic responses (i.e., taste reactivity [TR]) that are elicited by sucrose. In 2 experiments, rats had intraorally infused sucrose paired with LiCl injections for several trials, or they were injected with LiCl and had sucrose infused every 5 min during the 30-min postinjection period (data from A. C. Spector et al, 1988). In both experiments, ingestive TR responses decreased, whereas aversive TR responses increased over trials. Individual response components that comprise the ingestive and aversive categories followed the same trends of increase or decrease but changed at different rates as a function of number of trials or exposures. Overall, the array of response components could be projected onto a single unidimensional scale of palatability to capture the motivational states that ranged from acceptance to rejection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chorda tympani nerve transection disrupts taste aversion learning to potassium chloride, but not sodium chloride.

In Experiment 1, rats with chorda tympani nerve transection (CTX) acquired a LiCl-conditioned taste aversion to 0.1 M NaCl at the same rate as controls. After 3 conditioning trials, the aversion generalized to 0.03 and 0.3 M NaCl, but did not generalize to KCl (0.03, 0.1, and 0.3 M), in either the sham or CTX group. In Experiment 2, the sham group, but not the CTX group, formed an aversion to 0.1 M KCl after l trial. The CTX rats did form a moderate aversion after 2 conditioning trials. Following the 3rd trial, the CTX group did not suppress licking to 0.03 or 0.3 M KCl or any concentration of NaCl in relation to controls. Although there is strong evidence that CTX affects NaCl taste perception, these findings indicate that, under certain conditions, rats can nonetheless distinguish NaCl from KCl after such neurotomy. Moreover, CTX appears to have a substantial effect on the perceived intensity of KCl. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leukotriene activity modulation in asthma

Leukotrienes constitute a class of inflammatory mediators synthesised from arachidonic acid, a product of cell membrane metabolism. Synthesis occurs in the 5-lipoxygenase enzyme pathway, which produces several species of leukotrienes, each with characteristic biological activities. With regard to asthma, the leukotrienes are particularly important because of their ability to directly and potently mediate bronchoconstriction; in addition, they specifically stimulate the secretion of mucus into the airways and the extravasation of fluids and proteins into the airway tissues, both of which contribute to airway obstruction. A number of antileukotriene agents have been developed with the goal of modulating the inflammatory process in various disease states. These agents fall into 2 general classes: leukotriene receptor antagonists and leukotriene synthesis inhibitors. Results of antileukotriene agents in preclinical and clinical trials indicate that antileukotriene agents attenuate the response to challenges with inhaled leukotrienes, cold air, exercise, aspirin and allergen; in addition, they have shown efficacy in clinical asthma and have not been associated with serious adverse effects. Although results to date indicate that these medications are well tolerated and effective in the treatment of asthma, the recent approval by the FDA of 2 antileukotriene agents will give physicians further insight into how patients with asthma respond to them.     

Predicting progress in beginning reading: Dynamic assessment of phonemic awareness.

Investigates the ability of a dynamic measure of phonemic awareness to predict progress in beginning reading. 38 kindergartners who were nonreaders were assessed in the fall on receptive vocabulary, letter and word recognition, invented spelling, phoneme segmentation, phoneme deletion, and dynamic phoneme segmentation. They were retested near the end of the school year on reading, spelling, and phonemic awareness. The results of the multiple-regression analyses supported the hypothesis that dynamic assessment enhances the predictive utility of a phonemic awareness measure. Performance on dynamic phoneme segmentation was the best predictor of end-of-year reading scores and of growth in phonemic awareness. The study demonstrates the applicability of principles of dynamic assessment to the measurement of phonemic awareness and provides further evidence regarding the relationship between phonemic awareness and reading acquisition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of a social companion on the ultrasonic vocalizations and contact responses of 3-day-old rat pups.

Rat pups that are isolated in a novel environment emit ultrasonic calls. Vocalization in 3-day-old pups has been thought to be predominantly under thermal control (J. T. Allin and E. M. Banks, 1971). By the 2nd wk of life, ultrasonic vocalizations are reduced when pups are tested in the company of a single anesthetized littermate (S. E. Carden and M. A. Hofer, 1990; Hofer and H. Shair, 1978). In the present study, it was demonstrated that the vocalization rate of 3-day-old pups is also decreased when an anesthetized littermate is present in the isolation chamber. To determine whether this quieting was a function of the body heat of the companion, in a 2nd experiment, the axillary temperature of the companion was lowered until it was the same as the ambient temperature of the test chamber, 22°C. In the presence of a cool companion, ultrasonic vocalizations were also reduced. For the last experiment, a textured plastic surrogate was substituted for the littermate. Calls were not diminished in the presence of the surrogate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Method variance as an artifact in self-reported affect and perceptions at work: Myth or significant problem?

Method variance is an artifact of measurement that biases results when relations are explored among constructs measured by the same method. The existence of method variance was explored for affective and perceptual constructs frequently used in organizational research. Data from multitrait–multimethod analyses, studies of social desirability and acquiescence, and relation of self-report and records of absenteeism were presented. Little evidence for method variance as a biasing problem was found with these measures. I conclude that properly developed instruments of the type studied here are resistant to the method variance problem, but that validity of these instruments cannot be assumed on the basis of these results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)