Objective. To test the hypothesis that sex-related and joint compartment-related differences in the risk of osteoarthritis (OA) of the knee might be associated with variations in cartilage development, we investigated knee cartilage volume in healthy children. Methods. We studied 92 children who were randomly selected from among students in grades 3-12 of a single school in Hobart, Tasmania (49 boys, 43 girls; age range 9-18 years). Articular cartilage thickness and volume were determined at the patella, medial tibial compartment, and lateral tibial compartment by magnetic resonance imaging (MRI). Sagittal T1-weighted fat-suppressed MRI images were obtained and processed on an independent computer work station. Results. Males had significantly more knee cartilage than females. Sex accounted for 6-36% of the variation in cartilage thickness and volume, which was statistically significant at all sites. Even after adjustment for age, body mass index, bone area, and physical activity, males had 16-31% higher cartilage volume; this was most marked at the medial tibial site. In addition, lateral tibial thickness was greater than medial tibial thickness (5.9 versus 3.6 mm; P < 0.0001) and lateral tibial volume was greater than medial tibial volume (2,823 versus 2,299 l; P < 0.0001). Furthermore, physical activity was a significant explanatory factor for cartilage volume at all sites (R 2 7-14% depending on site; all P < 0.05). The most consistent activity association was with vigorous activity in the previous 2 weeks (difference between any vigorous activity versus none 22-25% greater; all P < 0.05). Conclusion. Sex-and joint compartment-related differences in cartilage development may be one explanation for variations in the pattern of knee OA seen in later life. Furthermore, the physical activity associations suggest that cartilage development is amenable to modification. Osteoarthritis (OA) is the major cause of disability in persons over the age of 65 years (1). Sex-related and joint compartment-related differences in knee OA are well described. Women have a 1.5-4 times higher risk than men (2) while medial compartment disease is 4 times more common than lateral compartment disease (3). The reasons for these variations are unclear at the present time. There is convincing evidence that other diseases of later life, such as ischemic heart disease, diabetes mellitus, and particularly, osteoporosis, are associated with childhood development (4,5). Although there are no data in humans with regard to early life exposures and risk of OA, a study in senescent moose linked a higher incidence of OA with a famine when the moose were weanlings (6). Defects in cartilage are widely considered to be the initial problem in OA (7), although this viewpoint is not shared by all investigators (8). However, cartilage development is poorly understood, and descriptive or etiologic data are few. In part, this is due to the lack of a noninvasive, accurate, in vivo method of assessing cartilage. Recently, magnetic resonance imaging (MRI) ha...

ABSTRACTabout hunting beluga, and Inuvialuit cosmology -the foundation of the knowledge systemwere documented through semi-structured questionnaires (n = 66), semi-structured interviews (n = 78) and focus group meetings (n = 3). This research furthers our understanding of how Inuvialuit view beluga health from the physical and behavioural characteristics of belugas, values and appropriate behaviours by harvesters and how observations made about beluga can be explained. To support the co-production of knowledge, a suite of local indicators was developed that bridged TEK about beluga condition, illness and disease with western science.

Monitoring methods based on Indigenous knowledge have the potential to contribute to our understanding of large watersheds. Research in large, complex, and dynamic ecosystems suggests a participatory approach to monitoring—that builds on the diverse knowledges, practices, and beliefs of local people—can yield more meaningful outcomes than a “one-size-fits-all” approach. Here we share the results of 12 community-based, participatory monitoring projects led by Indigenous governments and organizations in the Mackenzie River Basin (2015–2018). Specifically, we present and compare the indicators and monitoring methods developed by each of these community-based cases to demonstrate the specificity of place, culture, and context. A scalar analysis of these results suggests that the combination of core (common) indicators used across the basin, coupled with others that are meaningful at local level, create a methodological bricolage—a mix of tools, methods, and rules-in-use that are fit together. Our findings, along with those of sister projects in two other major watersheds (Amazon, Mekong), confront assumptions that Indigenous-led community-based monitoring efforts are too local to offer insights about large-scale systems. In summary, a networked approach to community-based monitoring that can simultaneously engage with local- and watershed-level questions of social and ecological change can address gaps in knowledge. Such an approach can create both practices and outcomes that are useful to local peoples as well as to those engaged in basin-wide governance.

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