A cost-effective method was designed to measure the behavioral response of negative phototaxis to high-intensity illumination in the sea urchin Glyptocidaris crenularis. Ninety sea urchins were randomly and equally di...A cost-effective method was designed to measure the behavioral response of negative phototaxis to high-intensity illumination in the sea urchin Glyptocidaris crenularis. Ninety sea urchins were randomly and equally divided into two aquaculture environment groups: a fasted group, which was starved during the experiment, and a fed group. After 10 months, the total mortality of each group was recorded. Then, 15 sea urchins were randomly selected from each group and behavioral responses to high-intensity illumination were investigated for each sea urchin. After the behavioral experiment, body measurements of the trial sea urchins were taken. The results reveal that food deprivation significantly affected test diameter (P〈0.01), body weight (P〈0.01), gonad weight (P〈0.0I), and gut weight (P〈0.01). Furthermore, food deprivation also affected negative phototaxis behaviors of time to rapid spine movement (P〈0.01), time to the 1 cm position (P〈0.05), and walking distance in 300 s (P〈0.01), but not time to body reaction (P〉0.05). The mortality rates of fasted and fed urchins were 6.7% and 0%, respectively. The present study provides evidence that food deprivation has a significant effect on phenotypic traits and behavioral responses to high-intensity illumination in the sea urchin G. crenularis. With this method, environmental stressors can be easily detected by measuring proper optional indicators. This study provides a new insight into measuring stress responses of sea urchins in aquaculture. However, further studies should be carried out to understand more environmental factors and to compare this potential behavioral method with immune, physiological, and epidemiological approaches.展开更多
This explorative study investigates 1) whether and how quantitative measures of writing can be applied in finding out about scoring raters' specific tendency in their scoring of EFL writing; 2) how the knowledge of...This explorative study investigates 1) whether and how quantitative measures of writing can be applied in finding out about scoring raters' specific tendency in their scoring of EFL writing; 2) how the knowledge of raters' tendency and scoring results would help verify the best way of combining raters' scores; and 3) how the prediction of the writing scores of EFL writing obtained by quantitative writing performance measures would match the real scores given by raters. Based on a tentative CAF framework of writing measures, raters' performance or tendency in their scoring was observed and certain patterns of similarities as well as differences were found among the raters. The resuks of multiple linear regressions indicate that all raters give prior attention to the aspect of accuracy in their scoring. Differences among raters are also obvious. When it comes to the combination of different raters' scores, the study also finds that weighted average is the best of the three ways of combining scores for this group of raters because it has yielded the best predicting scores than the "pure average". It is even slightly better than the results obtained by facet analysis in terms of some important indices such as R square and Durbin-Watson value. The matching of the predicted scores with the real scores is well over 50 percent. The results of the study are further discussed in relation to the application of wpm and the possible improvement of wpm framework. The methodological, theoretical and practical implications of the study have also been touched upon in the relevant part of the article.展开更多
Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is prese...Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk: interacting more equally with different females may be advantageous because ri- vals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains un- known if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males' mating preferences by scoring pre-mating (nipping) and mating behavior (gonopodial thrusting). Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male's behavior. A reduction in the strength of focal males' preferences was also seen after the rival male had an opportunity to mate with the focal male's preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both slimulus females not only the male's motivational state is reflected but also females' behavior such as avoidance of male sexual harassment [Current Zoology 58 (1): 84-94, 2012].展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A412)
文摘A cost-effective method was designed to measure the behavioral response of negative phototaxis to high-intensity illumination in the sea urchin Glyptocidaris crenularis. Ninety sea urchins were randomly and equally divided into two aquaculture environment groups: a fasted group, which was starved during the experiment, and a fed group. After 10 months, the total mortality of each group was recorded. Then, 15 sea urchins were randomly selected from each group and behavioral responses to high-intensity illumination were investigated for each sea urchin. After the behavioral experiment, body measurements of the trial sea urchins were taken. The results reveal that food deprivation significantly affected test diameter (P〈0.01), body weight (P〈0.01), gonad weight (P〈0.0I), and gut weight (P〈0.01). Furthermore, food deprivation also affected negative phototaxis behaviors of time to rapid spine movement (P〈0.01), time to the 1 cm position (P〈0.05), and walking distance in 300 s (P〈0.01), but not time to body reaction (P〉0.05). The mortality rates of fasted and fed urchins were 6.7% and 0%, respectively. The present study provides evidence that food deprivation has a significant effect on phenotypic traits and behavioral responses to high-intensity illumination in the sea urchin G. crenularis. With this method, environmental stressors can be easily detected by measuring proper optional indicators. This study provides a new insight into measuring stress responses of sea urchins in aquaculture. However, further studies should be carried out to understand more environmental factors and to compare this potential behavioral method with immune, physiological, and epidemiological approaches.
基金funded by China National Planning Office of Philosophy and Social Science(No.08XYY007)
文摘This explorative study investigates 1) whether and how quantitative measures of writing can be applied in finding out about scoring raters' specific tendency in their scoring of EFL writing; 2) how the knowledge of raters' tendency and scoring results would help verify the best way of combining raters' scores; and 3) how the prediction of the writing scores of EFL writing obtained by quantitative writing performance measures would match the real scores given by raters. Based on a tentative CAF framework of writing measures, raters' performance or tendency in their scoring was observed and certain patterns of similarities as well as differences were found among the raters. The resuks of multiple linear regressions indicate that all raters give prior attention to the aspect of accuracy in their scoring. Differences among raters are also obvious. When it comes to the combination of different raters' scores, the study also finds that weighted average is the best of the three ways of combining scores for this group of raters because it has yielded the best predicting scores than the "pure average". It is even slightly better than the results obtained by facet analysis in terms of some important indices such as R square and Durbin-Watson value. The matching of the predicted scores with the real scores is well over 50 percent. The results of the study are further discussed in relation to the application of wpm and the possible improvement of wpm framework. The methodological, theoretical and practical implications of the study have also been touched upon in the relevant part of the article.
文摘Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk: interacting more equally with different females may be advantageous because ri- vals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains un- known if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males' mating preferences by scoring pre-mating (nipping) and mating behavior (gonopodial thrusting). Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male's behavior. A reduction in the strength of focal males' preferences was also seen after the rival male had an opportunity to mate with the focal male's preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both slimulus females not only the male's motivational state is reflected but also females' behavior such as avoidance of male sexual harassment [Current Zoology 58 (1): 84-94, 2012].