Test Scores on Timed Exams Decline Over Time Without a Significant Increase in Physiological Stress

An article that appeared in JASS, issue 2015In today’s world, there is a lot of pressure to perform well on exams. Schools and workplaces rely on tests to evaluate individuals. While these institutions intend to test for cognitive function, there are a number of variables affecting these evaluations, such as stress, test anticipation, and other physiological factors. Our study examined the relationship between physiological stress and timed cognitive performance, specifically if the stress of test performance positively feedbacks on an individual’s respiratory rate, blood pressure, and heart rate. We predicted that these three physiological factors would increase as testing progressed, and that concurrently test performance would decline. Our results indicate that there was no significant change in heart rate or mean arterial blood pressure (MABP), although we did see a significant increase in respiratory rate following the first test section. Our data may therefore lead us to believe that students’ responses to testing situations are highly variable and do not collectively follow a general trend. A trend we did find to be statistically significant is declining performance in latter sections of the test. For test takers, it may be helpful to take note of their own stress patterns when taking exams and to adjust their strategies for maintaining calmness in order to potentially maintain high test performance throughout the evaluation

Rapid and selective detection of fatty acylated proteins using ω-alkynyl-fatty acids and click chemistry[S]

Progress in understanding the biology of protein fatty acylation has been impeded by the lack of rapid direct detection and identification methods. We first report that a synthetic ω-alkynyl-palmitate analog can be readily and specifically incorporated into GAPDH or mitochondrial 3-hydroxyl-3-methylglutaryl-CoA synthase in vitro and reacted with an azido-biotin probe or the fluorogenic probe 3-azido-7-hydroxycoumarin using click chemistry for rapid detection by Western blotting or flat bed fluorescence scanning. The acylated cysteine residues were confirmed by MS. Second, ω-alkynyl-palmitate is preferentially incorporated into transiently expressed H- or N-Ras proteins (but not nonpalmitoylated K-Ras), compared with ω-alkynyl-myristate or ω-alkynyl-stearate, via an alkali sensitive thioester bond. Third, ω-alkynyl-myristate is specifically incorporated into endogenous co- and posttranslationally myristoylated proteins. The competitive inhibitors 2-bromopalmitate and 2-hydroxymyristate prevented incorporation of ω-alkynyl-palmitate and ω-alkynyl-myristate into palmitoylated and myristoylated proteins, respectively. Labeling cells with ω-alkynyl-palmitate does not affect membrane association of N-Ras. Furthermore, the palmitoylation of endogenous proteins including H- and N-Ras could be easily detected using ω-alkynyl-palmitate as label in cultured HeLa, Jurkat, and COS-7 cells, and, promisingly, in mice. The ω-alkynyl-myristate and -palmitate analogs used with click chemistry and azido-probes will be invaluable to study protein acylation in vitro, in cells, and in vivo