Background： Many studies examining individual-level correlates in youth utilize self-report rather than objective measures of physical activity （PA）. This utilization of self-report may result in associations that ...Background： Many studies examining individual-level correlates in youth utilize self-report rather than objective measures of physical activity （PA）. This utilization of self-report may result in associations that are not present when examining objectively measured PA. The present study investigates the relationship between hypothesized correlates of PA with objectively and subjectively measured PA. Methods： Participating children （n 232, 101 males, mean age - 12.3 years） provided a minimum of four monitored days of PA （via accelerometer） and completed a survey assessing moderate-to-vigorous physical activity （MVPA）, sport competence, appearance, enjoyment, and self-efficacy. Height and weight were measured and body mass index （BMI） was calculated. Results： Hierarchical regression models controlling for sex, race, and BMI Z-score showed that only sex and BMI Z-score were significant correlates of objective MVPA while only sex was a significant correlate of objective total PA. However, in a separate model examining the relationship with subjective MVPA, enjoyment of PA and self-efficacy for PA were the only significant correlates of self-reported PA. Conclusion： Measuring MVPA via self-report versus accelerometry produces considerably different results in a sample of young adolescents. Future studies should use caution when selecting outcome measures if the intent is to identify modifiable correlates of MVPA in youth.展开更多
This study examines the effect of water-current speed on hematological,biochemical and immune parameters in juvenile tinfoil barb(B arbonymus schwanenfeldii). Blood samples were taken on days 1,23 and 45 from control ...This study examines the effect of water-current speed on hematological,biochemical and immune parameters in juvenile tinfoil barb(B arbonymus schwanenfeldii). Blood samples were taken on days 1,23 and 45 from control fish and from two training groups maintained at current speeds of 0.06 bl/s(body length per second),0.66 bl/s,and 1.92 bl/s,respectively. Significantly increased red-blood-cell counts and hematocrit were observed in the post-training groups on days 23 and 45. Significantly increased hemoglobin concentrations were also observed in the 1.92 bl/s group on days 23 and 45. In contrast,values of mean corpuscular volume were significantly lower in the 1.92 bl/s group than in the other groups on day 45. Nitroblue-tetrazolium-positive cells and lysozyme and superoxidase dismutase activities in the plasma increased significantly with increasing training intensity on days 23 and 45. Antibacterial activities were significantly increased in the trained groups compared with the control group on day 23; significantly elevated alkaline phosphatase activity was observed in the 1.92 bl/s groups on day 45. Therefore,training intensities of 0.66 and 1.92 bl/s enhanced the blood oxygen-carrying capability and plasma immune parameters of juvenile tinfoil barbs.展开更多
To understand mercury （Hg） toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder （Paralichthys olivaceus） and assessed the effects on growth and antioxidant responses. After Hg exposu...To understand mercury （Hg） toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder （Paralichthys olivaceus） and assessed the effects on growth and antioxidant responses. After Hg exposure （control, 5, 40, and 160 gg/L Hg） for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, hone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation （LPO）, which was also tissue-specific and dose- dependent. As Hg concentration increased, superoxide dismutase （SOD） and catalase （CAT） activities increased significantly, whereas glutathione S-transferase （GST） activity and glutathione （GSH） levels decreased significantly in the gills. SOD and glutathione peroxidase （GPx） activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.展开更多
Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations i...Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations in Turkey. The role of the social environment and social factors on PAP is being increasingly recognized. Although social capital(SC) indicators have been examined in high-income countries, there are few studies on developing countries. The aim of this study was to examine the relationship between SC indicators and PAP among Turkish adolescents.Methods: A survey was conducted among 19 high schools in 4 different cities in Turkey in 2016. A total of 506 female and 729 male high school students participated in this study. The dependent variable was overall PAP, which was measured using the short form of the International Physical Activity Questionnaire. The independent variables included self-perceived family, neighborhood, and school SC. Self-rated health and obesity status, measured by body mass index, were other study covariates in multiple binary logistic regression models. Chi-square tests were used to assess the differences between genders.Results: PAP levels were significantly different between males and females. A higher percentage of males reported PAP(77.4%) compared to females(51.0%). Among males, teacher–student interpersonal trust and informal social control were inversely associated with PAP, while high students interpersonal trust was positively associated with increased odds of PAP. For females, students interpersonal trust was inversely associated with PAP.Conclusion: Various SC indicators are associated with PAP for males and females. These associations are different from findings of studies conducted in developed countries. Therefore, health-promotion interventions and policies should consider gender and different social agents on the social and cultural background to improve PAP among Turkish adolescents.展开更多
基金funded by the Centers for Disease Control and Prevention(K01-DP001126)
文摘Background： Many studies examining individual-level correlates in youth utilize self-report rather than objective measures of physical activity （PA）. This utilization of self-report may result in associations that are not present when examining objectively measured PA. The present study investigates the relationship between hypothesized correlates of PA with objectively and subjectively measured PA. Methods： Participating children （n 232, 101 males, mean age - 12.3 years） provided a minimum of four monitored days of PA （via accelerometer） and completed a survey assessing moderate-to-vigorous physical activity （MVPA）, sport competence, appearance, enjoyment, and self-efficacy. Height and weight were measured and body mass index （BMI） was calculated. Results： Hierarchical regression models controlling for sex, race, and BMI Z-score showed that only sex and BMI Z-score were significant correlates of objective MVPA while only sex was a significant correlate of objective total PA. However, in a separate model examining the relationship with subjective MVPA, enjoyment of PA and self-efficacy for PA were the only significant correlates of self-reported PA. Conclusion： Measuring MVPA via self-report versus accelerometry produces considerably different results in a sample of young adolescents. Future studies should use caution when selecting outcome measures if the intent is to identify modifiable correlates of MVPA in youth.
基金Supported by the Science and Technology Projects of Guangdong Province(No.2012B020307002)the Science and Technology Projects of Guangzhou City(No.2010Z1-E401)the Fishery Science and Technology Popularization Projects of Guangdong Province(No.A201001H05)
文摘This study examines the effect of water-current speed on hematological,biochemical and immune parameters in juvenile tinfoil barb(B arbonymus schwanenfeldii). Blood samples were taken on days 1,23 and 45 from control fish and from two training groups maintained at current speeds of 0.06 bl/s(body length per second),0.66 bl/s,and 1.92 bl/s,respectively. Significantly increased red-blood-cell counts and hematocrit were observed in the post-training groups on days 23 and 45. Significantly increased hemoglobin concentrations were also observed in the 1.92 bl/s group on days 23 and 45. In contrast,values of mean corpuscular volume were significantly lower in the 1.92 bl/s group than in the other groups on day 45. Nitroblue-tetrazolium-positive cells and lysozyme and superoxidase dismutase activities in the plasma increased significantly with increasing training intensity on days 23 and 45. Antibacterial activities were significantly increased in the trained groups compared with the control group on day 23; significantly elevated alkaline phosphatase activity was observed in the 1.92 bl/s groups on day 45. Therefore,training intensities of 0.66 and 1.92 bl/s enhanced the blood oxygen-carrying capability and plasma immune parameters of juvenile tinfoil barbs.
基金Supported by the National Natural Science Foundation of China for Creative Research Groups (No. 41121064)the National High Technology Research and Development Program of China (863 Program) (No.2009AA09Z401)+1 种基金the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q07-02)the Public Interest Research Program in Marine Industry from the State Oceanic Administration of China (No. 200905019)
文摘To understand mercury （Hg） toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder （Paralichthys olivaceus） and assessed the effects on growth and antioxidant responses. After Hg exposure （control, 5, 40, and 160 gg/L Hg） for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, hone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation （LPO）, which was also tissue-specific and dose- dependent. As Hg concentration increased, superoxide dismutase （SOD） and catalase （CAT） activities increased significantly, whereas glutathione S-transferase （GST） activity and glutathione （GSH） levels decreased significantly in the gills. SOD and glutathione peroxidase （GPx） activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.
文摘Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations in Turkey. The role of the social environment and social factors on PAP is being increasingly recognized. Although social capital(SC) indicators have been examined in high-income countries, there are few studies on developing countries. The aim of this study was to examine the relationship between SC indicators and PAP among Turkish adolescents.Methods: A survey was conducted among 19 high schools in 4 different cities in Turkey in 2016. A total of 506 female and 729 male high school students participated in this study. The dependent variable was overall PAP, which was measured using the short form of the International Physical Activity Questionnaire. The independent variables included self-perceived family, neighborhood, and school SC. Self-rated health and obesity status, measured by body mass index, were other study covariates in multiple binary logistic regression models. Chi-square tests were used to assess the differences between genders.Results: PAP levels were significantly different between males and females. A higher percentage of males reported PAP(77.4%) compared to females(51.0%). Among males, teacher–student interpersonal trust and informal social control were inversely associated with PAP, while high students interpersonal trust was positively associated with increased odds of PAP. For females, students interpersonal trust was inversely associated with PAP.Conclusion: Various SC indicators are associated with PAP for males and females. These associations are different from findings of studies conducted in developed countries. Therefore, health-promotion interventions and policies should consider gender and different social agents on the social and cultural background to improve PAP among Turkish adolescents.
