In our trials, from 2007 to 2008, of mass production of seedlings of Hizikiafusiformis using synchronization techniques, problems of a ＂dark thalli＂ phenomenon and epiphytes contamination severely threatened the hea...In our trials, from 2007 to 2008, of mass production of seedlings of Hizikiafusiformis using synchronization techniques, problems of a ＂dark thalli＂ phenomenon and epiphytes contamination severely threatened the health of juvenile seedlings. In this investigation, we optimized conditions for improving the growth of juvenile seedlings. Seven string collectors were seeded with zygotes and a series of experiments were conducted including direct exposure to solar irradiance, co-culture with Ulva spp. and treatment with sodium hypochlorite. It was found that direct exposure to solar irradiance （maximum： 1 740 μmol photons/（m2.s）） for 2 h per day could efficiently enhance the growth of young seedlings and simultaneously inhibit the growth of epiphytic algae. In this treatment, 50-day old seedlings could reach an average of 0.44 cm in length and possess up to nine leaflets. However, a single treatment with 18-mmol/L sodium hypochlorite for 10 rain severely harmed 15-day old seedlings. In comparison, weekly treatment with 2.2-mmol/L sodium hypochlorite for 10 rain brought no apparent harm to seedlings and eliminated epiphytic algae efficiently. However, this treatment significantly increased the detachment rate of seedlings, Inoculating Ulva spp. onto the collector caused a dramatic decrease in the number of seedlings. However, the growth of the remaining seedlings appeared unhampered. All collectors except the control were daily sprayed with a high pressure water jet from the 84 day post fertilization. From the first day to 50th day, no ＂dark thallus＂ was observed on any of the seven collectors. We believe that well-timed daily exposure to solar irradiance would favor H. fusiformis in its early growing stages.展开更多
In a few decades, transition to adulthood has undergone significant changes in the manner and timing of attaining adulthood. The objective of the paper is to focus on the most significant transformations： the transit...In a few decades, transition to adulthood has undergone significant changes in the manner and timing of attaining adulthood. The objective of the paper is to focus on the most significant transformations： the transition to adulthood process has undergone in different European contexts, through the use of the findings of research performed in 2004 in Denmark, Germany and Italy. For the purpose of the comparison, in-depth analysis was performed of the interviews conducted on young people aged between 19 and 35, who had completed their education and were preparing to enter into the workplace. By means of the analysis of the interviews, the paper evaluates how youths perceive the passage from education to the workplace, taking into consideration the opportunities and resources provided by individual national contexts （social benefits, training and work opportunities） to facilitate the process of attainment of adult roles. The role played by family support to achieve transition is also analyzed. In particular, the type of support （financial, emotional and affective） provided by parents to their offspring during the various transition phases, with the aim of highlighting the existence of different parent-child relationships in the three countries examined.展开更多
基金Supported by the National High Technology Research and Development Program of China (863 Program) (Nos. 2006AA10A412 2006AA10A416)+1 种基金Main Program of National Science Infrastructure Platform, a project from the Ministry of Science and Technology of China (No. 2006DKA30470-017)a non-profit program from the Ministry of Agriculture of China (No. 200903030)
文摘In our trials, from 2007 to 2008, of mass production of seedlings of Hizikiafusiformis using synchronization techniques, problems of a ＂dark thalli＂ phenomenon and epiphytes contamination severely threatened the health of juvenile seedlings. In this investigation, we optimized conditions for improving the growth of juvenile seedlings. Seven string collectors were seeded with zygotes and a series of experiments were conducted including direct exposure to solar irradiance, co-culture with Ulva spp. and treatment with sodium hypochlorite. It was found that direct exposure to solar irradiance （maximum： 1 740 μmol photons/（m2.s）） for 2 h per day could efficiently enhance the growth of young seedlings and simultaneously inhibit the growth of epiphytic algae. In this treatment, 50-day old seedlings could reach an average of 0.44 cm in length and possess up to nine leaflets. However, a single treatment with 18-mmol/L sodium hypochlorite for 10 rain severely harmed 15-day old seedlings. In comparison, weekly treatment with 2.2-mmol/L sodium hypochlorite for 10 rain brought no apparent harm to seedlings and eliminated epiphytic algae efficiently. However, this treatment significantly increased the detachment rate of seedlings, Inoculating Ulva spp. onto the collector caused a dramatic decrease in the number of seedlings. However, the growth of the remaining seedlings appeared unhampered. All collectors except the control were daily sprayed with a high pressure water jet from the 84 day post fertilization. From the first day to 50th day, no ＂dark thallus＂ was observed on any of the seven collectors. We believe that well-timed daily exposure to solar irradiance would favor H. fusiformis in its early growing stages.
文摘In a few decades, transition to adulthood has undergone significant changes in the manner and timing of attaining adulthood. The objective of the paper is to focus on the most significant transformations： the transition to adulthood process has undergone in different European contexts, through the use of the findings of research performed in 2004 in Denmark, Germany and Italy. For the purpose of the comparison, in-depth analysis was performed of the interviews conducted on young people aged between 19 and 35, who had completed their education and were preparing to enter into the workplace. By means of the analysis of the interviews, the paper evaluates how youths perceive the passage from education to the workplace, taking into consideration the opportunities and resources provided by individual national contexts （social benefits, training and work opportunities） to facilitate the process of attainment of adult roles. The role played by family support to achieve transition is also analyzed. In particular, the type of support （financial, emotional and affective） provided by parents to their offspring during the various transition phases, with the aim of highlighting the existence of different parent-child relationships in the three countries examined.
