This study tested potential chemical defense of the green seaweed Avrainvillea elliottii against grazing by the sea urchin Lytechinus variegatus. We examined intraspecific variation of defensive chemicals in different parts of the thallus (margin, blade and stipe). We predicted that thallus parts making the greatest contributions to thallus fitness would show the greatest chemical deterrence to herbivory. The susceptibility of the whole alga and its different parts to consumption by L. variegatus was evaluated using assays consisting of powdered algae treated with natural concentrations of crude A. elliottii extract. Results from feeding evaluations showed that the crude extracts of whole plants and different thallus parts deterred consumption by this sea urchin. The results also supported our prediction that stronger chemical defenses occur in the more apical and younger areas of the thallus (margins), parts whose loss would result in the greatest reduction of fitness. These results provide added evidence supporting the ability of siphonaceous or coenocytic green macroalgae to concentrate defensive chemicals in growing parts.
Research has described the importance of orality at work and in everyday life but little agreement currently exists on how to theorize modern orality. This study explores how young adult literacy learners thought about and employed their textual (print) literacy within the oral contexts of their lives. We interviewed 88 mainly unemployed young persons undertaking literacy training to assess how their literacy fitted within their everyday lives, exploring their learning, employment, motivation, persistence, barriers to learning, and power dynamics. Respondents saw their textual literacy as situated within a matrix of everyday interpersonal communication more than as stand-alone functional skills, describing how literacy integrates with oral-experiential lifeworlds such as at work. Empirical evidence was provided to support the recent work of scholars who are building theory in the text–orality nexus. This study provides insights into the oral world of people with liminal (threshold) textual literacy; since such individuals are necessarily more oral than literate in their everyday life experience, they provide unique insights into how their orality intersects with use of textual information.