Extinction and retraining of simultaneous and successive flavor conditioning

In three experiments, rats received pairings of flavor conditioned stimuli with polycose unconditioned stimuli, in either a simultaneous or a sequential relation. Both temporal relations produced excellent conditioned increases in consumption of the flavors. Separate presentation of the flavors resulted in extinction in both cases. However, restoring the pairing of the flavor with polycose resulted in reconditioning only with the sequential, not with the simultaneous, relation.     

How much effort is needed to keep up with the literature relevant for primary care?

OBJECTIVES: Medicine must keep current with the research literature, and keeping current requires continuously updating the clinical knowledge base (i.e., references that provide answers to clinical questions). The authors estimated the volume of medical literature potentially relevant to primary care published in a month and the time required for physicians trained in medical epidemiology to evaluate it for updating a clinical knowledge base. METHODS: We included journals listed in five primary care journal review services (ACP Journal Club, DynaMed, Evidence-Based Practice, Journal Watch, and QuickScan Reviews). Finding little overlap, we added the 2001 "Brandon/Hill Selected List of Print Books and Journals for the Small Medical Library." We counted articles (including letters, editorials, and other commentaries) published in March 2002, using bibliographic software where possible and hand counting when necessary. For journals not published in March 2002, we reviewed the nearest issue. Five primary care physicians independently evaluated fifty randomly selected articles and timed the process. RESULTS: The combined list contained 341 currently active journals with 8,265 articles. Adjusting for publication frequency, we estimate 7,287 articles are published monthly in this set of journals. Physicians trained in epidemiology would take an estimated 627.5 hours per month to evaluate these articles. CONCLUSIONS: To provide practicing clinicians with the best current evidence, more comprehensive and systematic literature surveillance efforts are needed.     

Reliability of power output during rowing changes with ergometer type and race distance

Coaches, sport scientists and researchers assess rowing performance on-water and on a variety of ergometers. Ergometers are frequently used because of the easier assessment environment. However, there is limited information on the ability of rowers to reproduce mean power or time-trial time when using different rowing ergometers (Concept II and RowPerfect) or completing tests over different distances (500 m versus 2000 m races). To test the efficacy of an intervention on a rower's ability to produce power, or to monitor that ability, it is essential to determine a reliable rowing performance test. The per cent standard error of measurement in performance (assessed by mean power and time-trial time) of fifteen national standard rowers was determined for five repeated 500 m and two repeated 2000 m races on a Concept II and RowPerfect ergometer. The per cent standard error of measurement (% SEM) in mean power between 5x500m races, regardless of gender, was 2.8% (95% confidence limits (CL)=2.3 to 3.4%) for the Concept II ergometer and 3.3% (95% CL=2.5 to 3.9%) for the RowPerfect ergometer (n = 15). Over 2000 m the per cent standard error of measurement in mean power was 1.3% (95% CL 0.9 to 2.9%) for the Concept II ergometer and 3.3% (95% CL 2.2 to 7.0%) for the RowPerfect ergometer The results highlight an increase in per cent standard error of the mean during performance races of less than 2000m on the Concept II ergometer, and performance races on the RowPerfect ergometer compared with the Concept II ergometer over 500 m and 2000 m. The most appropriate protocol for testing the influence of an intervention on the ability of a rower to produce power would be 2000 m races on a Concept II ergometer.