The spacing effect: Improving electrocardiogram interpretation.

BACKGROUND: Accurate electrocardiogram (ECG) interpretation is critical for safe patient care, making this skill a necessary competency for medical school graduation. Improved long-term memory retention with repeated exposure to material is one of the most evidenced-based components of adult learning science. This curricular innovation aimed to determine if implementing spaced repetition and retrieval practice using ECG quizzes during the principal clinical year would improve ECG interpretation skills among medical students enrolled in a Longitudinal Integrated Clerkship (LIC). APPROACH: The curricular innovation applied the spacing effect and retrieval practice. Cognitive science demonstrates enhanced long-term retention through repeated interval exposure to learned material. Studies of spaced retrieval indicate that memory retention is enhanced through tests involving effortful recall. LIC students in an intervention group were exposed to the spacing effect with periodic ECG quizzes throughout their clinical clerkship year. EVALUATION: The results of the 17-item post-test for 140 students were analysed: LIC intervention, N = 54; block control, N = 62; and LIC control, N = 24. The ANOVA test was significant (p < 0.001). Games-Howell post hoc testing showed that the mean score in the LIC intervention group was significantly higher compared with the LIC control group (p < 0.001) and the block control group (p < 0.001). There was no significant difference between the LIC control and block control groups (p = 0.59). IMPLICATIONS: Spaced repetition of material through ECG quizzes improved ECG interpretation skills on an ECG post-test and mitigates the forgetting curve, maintaining student competency in ECG interpretation.

Intrinsic negative cell cycle regulation provided by PIP box- and Cul4Cdt2-mediated destruction of E2f1 during S phase.

E2F transcription factors are key regulators of cell proliferation that are inhibited by pRb family tumor suppressors. pRb-independent modes of E2F inhibition have also been described, but their contribution to animal development and tumor suppression is unclear. Here, we show that S phase-specific destruction of Drosophila E2f1 provides a novel mechanism for cell cycle regulation. E2f1 destruction is mediated by a PCNA-interacting-protein (PIP) motif in E2f1 and the Cul4(Cdt2) E3 ubiquitin ligase and requires the Dp dimerization partner but not direct Cdk phosphorylation or Rbf1 binding. E2f1 lacking a functional PIP motif accumulates inappropriately during S phase and is more potent than wild-type E2f1 at accelerating cell cycle progression and inducing apoptosis. Thus, S phase-coupled destruction is a key negative regulator of E2f1 activity. We propose that pRb-independent inhibition of E2F during S phase is an evolutionarily conserved feature of the metazoan cell cycle that is necessary for development.