No abstract

Predators frequently exert natural selection through differential consumption of their prey. However, predators may also cause prey mortality through nonconsumptive effects, which could cause selection if different prey phenotypes are differentially susceptible to this nonconsumptive mortality. Here we present an experimental test of this hypothesis, which reveals that nonconsumptive mortality imposed by predatory dragonflies causes selection on their damselfly prey favoring increased activity levels. These results are consistent with other studies of predator-driven selection, however, they reveal that consumption alone is not the only mechanism by which predators can exert selection on prey. Uncovering this mechanism also suggests that prey defensive traits may represent adaptations to not only avoid being consumed, but also for dealing with other sources of mortality caused by predators. Demonstrating selection through both consumptive and nonconsumptive predator mortality provides us with insight into the diverse effects of predators as an evolutionary force.

Topical 5-FU is used in a variety of dermatologic disease processes with a wide range of efficacy and levels of evidence. Based on extent and level of evidence, our disease-specific systematic review found that the evidence is strongest for topical 5-FU use in the treatment of actinic keratosis, squamous cell carcinoma, and basal cell carcinoma. This review serves as a comprehensive summary of topical 5-FU use in dermatology.

Objectives: Children with Down syndrome have an estimated 6-fold increased risk of developing celiac disease in the United States compared with the general population, yet the determination to screen for celiac disease in this population is not agreed upon. The objectives of this study are to assess the prevalence of celiac disease in children with Down syndrome in our center and compare features from this population identified clinically and through screening. Methods: This is a retrospective chart review of 1317 children with Down syndrome who received treatment at a single institution from 2011 to 2017. All participants (n = 90; 53.3% boys) met inclusion criteria of celiac disease diagnosis between 1 month and 22 years of age and Down syndrome. Clinical details were collected, which included the results from celiac disease screening tests, reason for diagnosis and/or testing, symptoms, nutrition notes, demographics, comorbidities, and outcomes. Results: Prevalence of celiac disease in our population of children with Down syndrome ages 3 years or older was 9.8%. Mean age at diagnosis was 9.24 years (SD = 4.98) with an average of 2.85 years (SD ± 3.52) lag from the onset of symptoms to diagnosis for children clinically identified in comparison with 1.69 years (SD ± 2.09) for children identified through routine screening. Eighty-two percentage of clinic patients received a diagnosis of celiac disease because of routine screening compared with clinical testing based on identified symptoms alone. Conclusion: Our results suggest the need for routine celiac disease screening in children with Down syndrome to improve case-finding and avoid diagnostic delay.