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991.
Eccentric exercise has been associated with an increase in serial sarcomere number in some studies,1 but not in others.2 Similarly,increasing excursion of muscles resulted in sarcomerogenesis in some studies using growing animals,3 but not in others using skeletally mature animals.4 However,chronic elongation and chronic shortening appears to be a strong regulator of sarcomere number increase5,6 and decrease,5,7 respectively,in animal models.Despite an abundance of research on the regulation of sarcomerogenesis under a variety of conditions,the mechanisms underlying in series sarcomere number adaptations in skeletal muscles remain a puzzle,especially in non-invasive human studies where measurements of sarcomerogenesis following interventions have not been possible to date.  相似文献   
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Obesity is a disease that has become an epidemic in economically developed countries,and manifests itself at increasing rates in economically developing countries.Obesity is associated with a variety of comorbidities,such as metabolic disease,diabetes,cardiovascular diseases,and musculoskeletal disorders,all resulting in tremendous costs to health care systems around the world,a reduced capacity for work,and reduced quality of life for people with obesity,coupled with physical inactivity,thereby producing a vicious circle of inactivity-induced diseases that enhances obesity.  相似文献   
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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.  相似文献   
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This article provides an empirical investigation of the effects of the ownership and organizational structure on the performance of cultural institutions. More specifically, we consider how museums are effective in their function of disseminating culture to audiences and contributing to the local development. By exploiting a unique data set based on the 2011 census of Italian museums, we develop performance indices of accessibility, visitors’ experience, web visibility and promotion of the local cultural context. Using count data models, we regress such measures on the type of organization. We distinguish between governmental museums, public museums whose administration is either outsourced or has financial autonomy and private museums. We control for the most salient characteristics of a museum, competition pressure and some proxies of potential audience. Our evidence shows that private museums, public museums with financial autonomy and outsourced museums outperform public museums run as sub-units of culture departments. This paper contributes to the cultural economics and public policy and administration literature by adding insights into the effect of outsourcing and administrative decentralization in the public cultural sector.  相似文献   
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