Impact of age on host responses to diet-induced obesity:Development of joint damage and metabolic set points

Background:Osteoarthritis is one of the leading causes of pain and disability worldwide,and a large percentage of patients with osteoarthritis are individuals who are also obese.In recent years,a series of animal models have demonstrated that obesity-inducing diets can result in synovial joint damage(both with and without the superimposition of trauma),which may be related to changes in percentage of body fat and a series of low-level systemic inflammatory mediators.Of note,there is a disparity between whether the dietary challenges commence at weaning,representing a weanling onset,or at skeletal maturity,representing an adult onset of obesity.We wished to evaluate the effect ofthe dietary exposure time and the age at which animals are exposed to a high-fat and high-sucrose(HFS) diet to determine whether these factors may result in disparate outcomes,as there is evidence suggesting that these factors result in differential metabolic disturbances.Based on dietary exposure time,we hypothesized that rats fed an HFS diet for 14 weeks from weaning(HFS Weanling) would demonstrate an increase in knee joint damage scores,whereas rats exposed to the HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult) and rats exposed to a standard chow diet(Chow)would not display an increase in knee joint damage scores.Methods:Male Sprague-Dawley rats were fed either an HFS diet for 14 weeks from weaning(HFS Weanling) or an HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult).At sacrifice,joints were scored using the modified Mankin Criteria,and serum was analyzed for a defined subset of inflammatory markers(Interleukin-6,leptin,monocyte chemoattractant protein-1,and tumor necrosis factorα).Results:When the HFS Weanling and HFS Adult groups were compared,both groups had a similar percent of body fat,although the HFS Weanling group had a significantly greater body mass than the HFS Adult group.The HFS Weanling and HFS Adult animals had a significant increase in body mass and percentage of body fat when compared to the Chow group.Although knee joint damage scores were low in all 3 groups,we found,contrary to our hypothesis,that the HFS Adult group had statistically significant greater knee joint damage scores than the Chow and HFS Weanling groups.Furthermore,we observed that the HFS Weanling group did not have significant differences in knee joint damage scores relative to the Chow group.Conclusion:These findings indicate that the HFS Weanling animals were better able to cope with the dietary challenge of an HFS diet than the HFS Adult group.Interestingly,when assessing various serum proinflammatory markers,no significant differences were detected between the HTS Adult and HFS Weanling groups.Although details regarding the mechanisms underlying an increase in knee joint damage scores in the HFS Adult group remain to be elucidated,these findings indicate that dietary exposure time maybe less important than the age at which an HFS diet is introduced.Moreover,increases in serum proinflammatory mediators do not appear to be directly linked to knee joint damage scores in the HFS Weanling group animals but may be partially responsible for the observed knee joint damage in the adults over the very short time of exposure to the HFS diet.     

Metacognition and Human Performance Improvement

An understanding of the uses of meta-cognition provides a powerful tool toward developing quality and efficiency in task learning and performance. Metacognition is the executive controller of cognitive processes responsible both for self regulated learning and work performance outcomes. Comprehension monitoring and motivation are two prime components of metacognition which are responsible for commitment to, and definition of, goals, monitoring progress toward goals, and activating the appropriate thinking skills to achieve goals. Specific thinking skill categories of attention, organization, and elaboration are described with examples of how specific techniques in each category can optimize learning and job performance. Research on training of metacognitive skills through both detached and embedded skill-development programs is reviewed. In addition, ways to compensate for metacognitive skills when training is not cost-effective are described. The relationship between metacognitive skills and effective management of work performance is stressed.     

Surveying unstructured time of adults with mental retardation living in two community settings: A search for normalization

Abstract

We designed a survey to assess whether 40 randomly selected individuals, equally divided across two settings (ICF/MR, minigroup home), differed in the amounts of time spent in the community, the people with whom unstructured activities were performed, and the choice maker of unstructured activities performed in the community or in homes. Time spent in unstructured activities was divided into four subsets: performed by self, with a peer, with staff, and with family. An analysis of variance (ANOVA) indicated that individuals living in ICF/MR homes spent more time in the community with staff and made fewer choices of their unstructured activities than those living in minigroup homes. The analyses also indicated that for those retaining their own legal guardianship and living in ICF/MR homes continued to spend less time in activities they chose themselves. Of those variables reaching statistical significance, we questioned meaningful interpretations based on alternative interpretations of the raw data.     

K–12 and University Educators Working Together Toward Change: Initiating a Conversation About Practice

This case study of a joint school/university professional development opportunity explored how 12 practitioners came together to examine change in light of discrepancies between current practice in local schools and promising practices recommended in the literature for students identified as having significant disabilities. The group met monthly over the course of one school year to study action research and to examine aspects of individual practice and their emerging identity as a community of learners. Participants explored perceptions about promising practice relative to actual practice engaged in by K–12 teachers, the impact of ongoing structured conversation on individual practice, and the impact of group membership for both individual participants and school/university partnerships. After one academic year, participants reported that the impact of this structured conversation was highly meaningful with respect to positive change in individual practice, the creation of a new support network for participants, and the development of new understandings between university and K–12 practitioners. Findings are discussed in light of implications for researchers, teacher educators, and K–12 practitioners in their various roles as agents of social change.