Technological development has led to the emergence of new substances with many different purposes generating a new profile of pollutants in waterways. Among these, endocrine disruptors, such as 17EE （17ct-ethinylestr...Technological development has led to the emergence of new substances with many different purposes generating a new profile of pollutants in waterways. Among these, endocrine disruptors, such as 17EE （17ct-ethinylestradiol）, are of great importance due to their wide application and harmful consequences to the environment, human health and animals. The inefficiency of most water treatment processes in withdrawing such substances poses a global concern for the development of effective and environmentally clean methods. The electrochemical remediation processes appear as a powerful and ＂green＂ alternative for waste removal of organic or inorganic pollutants from complex environments, such as geosphere and hydrosphere. The research focus in this field is mostly related to the optimization of electronic devices with higher （photo） catalytic efficiency, whereas the starting material remains based on metal and carbon conventional electrodes. In the present study, the anodic removal process of 17ct-ethinylestradiol at carbon cardboards was investigated in stationary and hydrodynamic conditions. The influence of pH and applied potential were evaluated, always taking into account the transposition of scale and environmental aspects. Thus, the principle of hormone removal showed to be strictly related to such parameters. It was observed that mild alkaline medium favors the anodic oxidation, whereas neutral and mild acid ones lead to higher adsorption at carbon surface. Also, when the applied potential was higher than 1.25 V, the electrochemical oxidation rate increased, and the adsorption was decreased. Furthermore, the removal efficiency of ! 7EE showed to be lower, the flow rate was higher.展开更多
Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the ...Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, re- productive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many her- maphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites＇ eggs. In the simulta- neously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced dur- ing development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress result- ing in a reduction of the overall reproductive resources up to the first egg laying .展开更多
文摘Technological development has led to the emergence of new substances with many different purposes generating a new profile of pollutants in waterways. Among these, endocrine disruptors, such as 17EE （17ct-ethinylestradiol）, are of great importance due to their wide application and harmful consequences to the environment, human health and animals. The inefficiency of most water treatment processes in withdrawing such substances poses a global concern for the development of effective and environmentally clean methods. The electrochemical remediation processes appear as a powerful and ＂green＂ alternative for waste removal of organic or inorganic pollutants from complex environments, such as geosphere and hydrosphere. The research focus in this field is mostly related to the optimization of electronic devices with higher （photo） catalytic efficiency, whereas the starting material remains based on metal and carbon conventional electrodes. In the present study, the anodic removal process of 17ct-ethinylestradiol at carbon cardboards was investigated in stationary and hydrodynamic conditions. The influence of pH and applied potential were evaluated, always taking into account the transposition of scale and environmental aspects. Thus, the principle of hormone removal showed to be strictly related to such parameters. It was observed that mild alkaline medium favors the anodic oxidation, whereas neutral and mild acid ones lead to higher adsorption at carbon surface. Also, when the applied potential was higher than 1.25 V, the electrochemical oxidation rate increased, and the adsorption was decreased. Furthermore, the removal efficiency of ! 7EE showed to be lower, the flow rate was higher.
文摘Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, re- productive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many her- maphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites＇ eggs. In the simulta- neously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced dur- ing development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress result- ing in a reduction of the overall reproductive resources up to the first egg laying .
