A scoping review of successful strategies for passing the American Board of Surgery certifying examination.

Background: This scoping review identifies existing literature that investigates what factors contribute to success on the American Board of Surgery (ABS) Certifying Exam (CE) to provide practical, evidence-based recommendations. Methods: A Pubmed search was completed utilizing the preferred reporting items for systematic reviews and meta-analysis extension for scoping review (PRISMA-ScR) method. Results: Of 4368 articles identified, 45 articles met criteria for review. Manuscripts were placed into one of five categories: predictors from medical school, program interventions, modifiable candidate factors, the effect of mock oral exams, and those factors shown not to provide benefit for CE preparation. Conclusions: A variety of factors have either been shown to provide benefit for or be predictive of CE performance. Acknowledgement of these factors can provide benefit to both surgery residents as well as surgery programs. Despite these findings, research into these factors is generally of low quality, prompting the need for ongoing, high-quality investigations.

Guanine-based structural coloration as an indicator of oxidative stress in a cichlid fish.

Vertebrate pigmentation is known to be influenced by oxidative stress, but few studies have tested the hypothesis that structural coloration can be similarly affected. We tested whether fish iridophores, which produce structural color using guanine stacks, might be affected by the prooxidant-antioxidant balance of the animal. Specifically, we hypothesized that convict cichlids (Amatitlania nigrofasciata) metabolize guanine present in iridophores to uric acid, an antioxidant, in response to oxidative damage. We used Hunter's contrast gloss and high performance liquid chromatography to determine whether dietary guanine supplementation allows fish to maintain their structural coloration despite oxidative stress induced via ultraviolet-B (UV-B) radiation. We found that dietary guanine was associated with greater skin gloss, and that exposure to UV-B light reduced glossiness. UV-B exposure did not increase oxidative damage (acrolein) or total antioxidant capacity in the skin or liver. Our experiment did not detect effects of dietary guanine or UV-B light on uric acid, but uric acid was positively related to antioxidant capacity. Our results support the hypothesis that structural color in fish may be altered by environmental stressors such as exposure to UV light, and highlight the need for future studies to consider the role of iridophores in condition-dependent visual signaling.