Grateloupia turuturu is a commercial red alga with potential value in nutraceuticals and pharmaceuticals. To supplement information on its life history and verify whether carpospores can be used for seedling culture, ...Grateloupia turuturu is a commercial red alga with potential value in nutraceuticals and pharmaceuticals. To supplement information on its life history and verify whether carpospores can be used for seedling culture, early development of G. turuturu was investigated under culture conditions （27~C, 10-13 ~mol/（mZ.s） in irradiance, photoperiod 10：14 h L：D）. Three physiological stages were recognized by continuous microscopic observation： division stage, discoid crust stage, and juvenile seedling stage. At the beginning of the division stage, the carpospores developed germ tubes into which the carpospore protoplasm was evacuated, and then the carpospore protoplasm in the germ tubes began to divide continuously until discoid crusts formed. Finally, upright thalli appeared on the discoid crusts and developed into juvenile seedlings. It took about 60 days for carpospores to develop into juvenile seedlings. The growth parameters, including germination rate for carpospores and discoid crust diameter, were recorded. These results contribute more information on the life cycle, and at the same time are of great significance in the scaling-up of artificial seedling cultures of G. turuturu.展开更多
Background： Among numerous health benefits, sports participation has been shown to reduce the risk of overweight and obesity in children and adolescents. Schools represent an ideal environment for increasing sports p...Background： Among numerous health benefits, sports participation has been shown to reduce the risk of overweight and obesity in children and adolescents. Schools represent an ideal environment for increasing sports participation, but it is unclear how access and choice influence participation and whether characteristics of the school sports program differentially influence boys＇ and girls＇ participation. The purpose of this study was to evaluate the characteristics of high school athletic programs and determine the extent to which these characteristics influenced boys＇ and girls＇ sports team participation. Methods： Longitudinal telephone surveys were conducted with 1244 New Hampshire and Vermont students. Students self-reported their sports team participation at baseline （elementary school） and follow-up （high school）. High school personnel were surveyed to assess sports oppor- tunities, which were defined for this analysis as the number of sports offered per 100 students （i.e., choice） and the percent of sports offered that did not restrict the number of players （i.e., access）. Results： Approximately 70% of children participated on at least one sports team, including 73% of boys and 66% of girls. We detected sta- tistically significant interactions between sex and two school opportunity variables： 1） the number of sports offered per 100 students （i.e., choice） and 2） the percent of sports offered that did not restrict the number of players （i.e., access）. After controlling for children＇s baseline sports participation and other covariates, boys were more likely to play on at least one sports team per year if their school did not restrict participation in the most popular sports （relative risk, RR = 1.12, p 〈 0.01）; in contrast, girls were more likely to play on at least one sports team per year if their school offered a wider variety of sports （RR = 1.47, p 〈 0.001）. Conclusion： Sports participation has previously been shown to confer a number of health benefits; as such, school sports programs may be an important, effective, and underused target for public health efforts, including obesity prevention programs. Efforts to increase physical activity among youth should consider both access and choice in school athletic programs. Schools may need to use different strategies to increase sports participation in boys and girls.展开更多
Focusing on human health in the 21st century is the common theme of the international community, with the continuous development of human society, the continuous improvement of quality of life, new health problems con...Focusing on human health in the 21st century is the common theme of the international community, with the continuous development of human society, the continuous improvement of quality of life, new health problems continue to appear, threatening human health, which has aroused great attention from the international community, it has taken the appropriate strategy, intervention effects of the disease on human health caused by the literature review, methods of induction and deduction in the current life of health, the impact of lifestyle on health, sports health effects were discussed with, so that people have a more clear understanding, of the health and quality of life of people.展开更多
Contemporary college students will be the future mainstay of the world and the country. It is significant to accept education of the Olympic culture. While they know the long and broad Olympic culture, they can also i...Contemporary college students will be the future mainstay of the world and the country. It is significant to accept education of the Olympic culture. While they know the long and broad Olympic culture, they can also inherit the Olympic spirit of mutual understanding, friendship, solidarity and fair competition, know that the world needs to be cleaner, more humane, more united.展开更多
基金Supported by the Natural Science Foundation of Shandong Province,China(No.Y2007D42)
文摘Grateloupia turuturu is a commercial red alga with potential value in nutraceuticals and pharmaceuticals. To supplement information on its life history and verify whether carpospores can be used for seedling culture, early development of G. turuturu was investigated under culture conditions （27~C, 10-13 ~mol/（mZ.s） in irradiance, photoperiod 10：14 h L：D）. Three physiological stages were recognized by continuous microscopic observation： division stage, discoid crust stage, and juvenile seedling stage. At the beginning of the division stage, the carpospores developed germ tubes into which the carpospore protoplasm was evacuated, and then the carpospore protoplasm in the germ tubes began to divide continuously until discoid crusts formed. Finally, upright thalli appeared on the discoid crusts and developed into juvenile seedlings. It took about 60 days for carpospores to develop into juvenile seedlings. The growth parameters, including germination rate for carpospores and discoid crust diameter, were recorded. These results contribute more information on the life cycle, and at the same time are of great significance in the scaling-up of artificial seedling cultures of G. turuturu.
基金funded by the U.S.National Institute of Environmental Health Sciences(ES014218)the U.S.National Cancer Institute(CA94273)
文摘Background： Among numerous health benefits, sports participation has been shown to reduce the risk of overweight and obesity in children and adolescents. Schools represent an ideal environment for increasing sports participation, but it is unclear how access and choice influence participation and whether characteristics of the school sports program differentially influence boys＇ and girls＇ participation. The purpose of this study was to evaluate the characteristics of high school athletic programs and determine the extent to which these characteristics influenced boys＇ and girls＇ sports team participation. Methods： Longitudinal telephone surveys were conducted with 1244 New Hampshire and Vermont students. Students self-reported their sports team participation at baseline （elementary school） and follow-up （high school）. High school personnel were surveyed to assess sports oppor- tunities, which were defined for this analysis as the number of sports offered per 100 students （i.e., choice） and the percent of sports offered that did not restrict the number of players （i.e., access）. Results： Approximately 70% of children participated on at least one sports team, including 73% of boys and 66% of girls. We detected sta- tistically significant interactions between sex and two school opportunity variables： 1） the number of sports offered per 100 students （i.e., choice） and 2） the percent of sports offered that did not restrict the number of players （i.e., access）. After controlling for children＇s baseline sports participation and other covariates, boys were more likely to play on at least one sports team per year if their school did not restrict participation in the most popular sports （relative risk, RR = 1.12, p 〈 0.01）; in contrast, girls were more likely to play on at least one sports team per year if their school offered a wider variety of sports （RR = 1.47, p 〈 0.001）. Conclusion： Sports participation has previously been shown to confer a number of health benefits; as such, school sports programs may be an important, effective, and underused target for public health efforts, including obesity prevention programs. Efforts to increase physical activity among youth should consider both access and choice in school athletic programs. Schools may need to use different strategies to increase sports participation in boys and girls.
文摘Focusing on human health in the 21st century is the common theme of the international community, with the continuous development of human society, the continuous improvement of quality of life, new health problems continue to appear, threatening human health, which has aroused great attention from the international community, it has taken the appropriate strategy, intervention effects of the disease on human health caused by the literature review, methods of induction and deduction in the current life of health, the impact of lifestyle on health, sports health effects were discussed with, so that people have a more clear understanding, of the health and quality of life of people.
文摘Contemporary college students will be the future mainstay of the world and the country. It is significant to accept education of the Olympic culture. While they know the long and broad Olympic culture, they can also inherit the Olympic spirit of mutual understanding, friendship, solidarity and fair competition, know that the world needs to be cleaner, more humane, more united.
