Re-evaluating the morphological evidence for the re-evolution of lost mandibular teeth in frogs.

Dollo's law of irreversibility states that once a complex structure is lost, it cannot be regained in the same form. Several putative exceptions to Dollo's law have been identified using phylogenetic comparative methods, but the anatomy and development of these traits are often poorly understood. Gastrotheca guentheri is renowned as the only frog with teeth on the lower jaw.

Development and regeneration of the crushing dentition in skates (Rajidae).

Sharks and rays (elasmobranchs) have the remarkable capacity to continuously regenerate their teeth. The polyphyodont system is considered the ancestral condition of the gnathostome dentition. Despite this shared regenerative ability, sharks and rays exhibit dramatic interspecific variation in their tooth morphology.

Effect of Visual Art School-Based Stroke Intervention for Middle School Students.

Background: Community stroke awareness initiatives have traditionally been used to expand knowledge of stroke signs and risk factors to high-risk adult populations. Here, we use a novel unfettered, visual art-based approach for an elementary school initiative to raise stroke awareness.

Methods: Seventh graders in a middle school art class received stroke awareness training during the course of the 2015 to 2016 school year through their teacher in the visual arts class.