ALH fibrocartilage appears to be particularly prone to calcification, which may explain higher pain levels in individuals with a high degree of ALH calcification independent of age and histological degeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1248-1255, 2018.

The long-spined sea urchin Diadema antillarum was once an abundant reef grazing herbivore throughout the Caribbean. During the early 1980s, D. antillarum populations were reduced by > 93% due to an undescribed disease. This event resulted in a lack of functional reef herbivory and contributed to ongoing ecological shifts from hard coral towards macroalgae dominated reefs. Limited natural recovery has increased interest in a range of strategies for augmenting herbivory. An area of focus has been developing scalable ex situ methods for rearing D. antillarum from gametes. The ultimate use of such a tool would be exploring hatchery origin restocking strategies. Intensive ex situ aquaculture is a potentially viable, yet difficult, method for producing D. antillarum at scales necessary to facilitate restocking. Here we describe a purpose-built, novel recirculating aquaculture system and the broodstock management and larval culture process that has produced multiple D. antillarum cohorts, and which has the potential for practical application in a dedicated hatchery setting. Adult animals held in captivity can be induced to spawn year-round, with some evidence for annual and lunar periodicity. Fecundity and fertilization rates are both consistently very high, yet challenges persist in both late stage larval development and early post-settlement survival. Initial success was realized with production of 100 juvenile D. antillarum from ~ 1200 competent larvae. While the system we describe requires a significant level of investment and technical expertise, this work advances D. antillarum culture efforts in potential future hatchery settings and improves the viability of scalable ex situ production for population enhancement.

Objective Recent data reports that youth experience greater weight gain during summer than during school months. We tested the hypothesis that a difference in total energy expenditure (TEE) between school and summer months exists and may contribute to summer weight gain. Subjects and Methods A secondary analysis was performed on cross-sectional TEE data from school-age, sedentary African American and Caucasian youth based in or near the District of Columbia who were at-risk for adult obesity because they had BMI≥85th percentile or had overweight parents. TEE was estimated from 18-O and deuterium measurements during 1-week intervals using urine samples collected after ingestion of doubly-labeled water. Differences in summer and school time TEE were assessed using ANCOVA. The data were adjusted for fat-free mass as determined by deuterium dilution to adjust for the effect of body size on TEE. Results Data were collected from 162 youth (average age 10±2 years, BMI 28±8 kg/m2, and BMI z-score 1.96+0.96). Of these, 96 youth had TEE measured during the school year (September – June); 66 different youths had TEE measured during summer months (June – August). After adjustment for fat-free mass, average summertime TEE was 2450±270 kcal/day and average school-time TEE was 2510±350 kcal/day (p=0.26). Conclusion No difference in TEE was detected between the school year and the summer months. These data suggest that seasonal differences in youth weight gain are not necessarily due to differences in energy expenditures.

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