[ Objective ] This paper aimed to study the sexual dimorphism of Rana guentheri. [ Method ] Sixty-seven Rana guentheri were collected in Zhaoqing ar- ea to measure their morphological indexes, count the brood amount o...[ Objective ] This paper aimed to study the sexual dimorphism of Rana guentheri. [ Method ] Sixty-seven Rana guentheri were collected in Zhaoqing ar- ea to measure their morphological indexes, count the brood amount of female Rana guentheri and study sexual dimorphism and female reproductive characteristics . [Result] The average snout-vent length of male Rana guentheri was (75.07 ± 1.21 ) mm and the average snout-vent length of female Rana guentheri was (78.67 ± 1.23 ) mm. The snout-vent length and weight of female Rana guentheri were significantly different from that of male Rana guentheri, which illustrated that snout-vent length and body weight of Rana gttentheri had significant sexual dimorphism. The sexual dimorphism index was 0.05. The Local morphological inde- xes of Rana guentheri were positively related with the snout-vent length. The average brood amount of female Rana guentheri was 4 916. The snout-vent length and body weight were positively related with the brood amount of female Rana guentheri. [ Conclusion] Rana guentheri in Zhaoqing area had obvious sexual dimor- phism.展开更多
Guppies( Poecilia reticulata) are considered a candidate model species for the identification and testing of endocrine-disrupting chemicals. Male guppies may be used to address the challenge of making potential linkag...Guppies( Poecilia reticulata) are considered a candidate model species for the identification and testing of endocrine-disrupting chemicals. Male guppies may be used to address the challenge of making potential linkages between alterations of biomarkers, both at the cellular and organ level, and adverse outcomes. In the present study, a predictive relationship between sex characteristics and reproductive output was observed in male guppies that underwent a long-term toxicity test with 0.5 μg/L 17 β-estradiol administered during the juvenile period. Radioimmunoassay and western blot analyses demonstrated that 17 β-estradiol exposure caused a significant increase in testicular 17 β-estradiol levels as well as the induction of exposure biomarkers, namely hepatic vitellogenin. Exposure to 17 β-estradiol also caused a significant decrease in testosterone levels, which consequently reduced the gonadosomatic index, sperm counts, and the coloration index. These changes of male sexual characteristics further translated into adverse influences on reproduction, as measured by a decrease in offspring production and survival rate. Our results suggest that the above-mentioned sexual characteristics of male guppies may be considered potential in vivo biomarkers of estrogen effects on reproduction.展开更多
Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Po...Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Polypedates megacephalus and P. mutus are two sympatric and morphologically similar tree frogs, but it remains unknown whether their calls are associated with body size. In this study, we compared call characteristics of these two species and investigated any potential relationships with body size. We found that P. megacephalus, males produced six call types which consisting of three distinct notes, while P. mutus males produced five types consisting of two types of notes. Dominant frequency, note duration, pulse duration, and call duration exhibited significant interspecific differences. In P. megacephalus, one note exhibited a dominant frequency that was negatively correlated with body mass, snout-vent length, head length, and head width. In P. mutus, the duration of one note type was positively correlated with body mass and head width. These differences in call characteristics may play an important role in interspecific recognition. Additionally, because interspecific acoustic variation reflects body size, calls may be relevant for sexual selection. Taken together, our results confirmed that calls are a valid tool for distinguishing between the two tree-frog species in the field.展开更多
This study evaluates variables concerning demographic characteristics for all adult male offenders convicted of Child Sexual Abuse(CSA)aged 0–17 in Malmö,Sweden between 2013 and 2018.All convictions(n=18)based o...This study evaluates variables concerning demographic characteristics for all adult male offenders convicted of Child Sexual Abuse(CSA)aged 0–17 in Malmö,Sweden between 2013 and 2018.All convictions(n=18)based on court documents from the District Court,the Court of Appeals and information from the Swedish Tax Agency were reviewed.A total of 30 victims were identified.Frequency analyses show that the most common features were that of a single offender,averaging 25 years old,with a non-Swedish background and a high school degree.The predominately extrafamilial CSA(i.e.committed by an acquaintance to the family)occurred in a private setting and consisted of penetrative acts.Girls averaging 13years old were abused multiple times,under fear and pressure.Although assumptions based on these results are preliminary,they provide a clearer image of the typical circumstances under which CSA occurred within this time frame and geographical location.This study is a first attempt to construct an overview of demographic characteristics of CSA.As more data are gathered from this region,more sophisticated analyses can be conducted,providing stronger generalizations.Information of this kind may be important for research,classification of offender profiling and in case linking.展开更多
基金Supported by National Natural Science Foundation of China(31271124)Natural Foundation Project of Guangdong Province(s2013010016062)Planned Project for Innovation and Entrepreneurship by Undergraduate(DC201455)
文摘[ Objective ] This paper aimed to study the sexual dimorphism of Rana guentheri. [ Method ] Sixty-seven Rana guentheri were collected in Zhaoqing ar- ea to measure their morphological indexes, count the brood amount of female Rana guentheri and study sexual dimorphism and female reproductive characteristics . [Result] The average snout-vent length of male Rana guentheri was (75.07 ± 1.21 ) mm and the average snout-vent length of female Rana guentheri was (78.67 ± 1.23 ) mm. The snout-vent length and weight of female Rana guentheri were significantly different from that of male Rana guentheri, which illustrated that snout-vent length and body weight of Rana gttentheri had significant sexual dimorphism. The sexual dimorphism index was 0.05. The Local morphological inde- xes of Rana guentheri were positively related with the snout-vent length. The average brood amount of female Rana guentheri was 4 916. The snout-vent length and body weight were positively related with the brood amount of female Rana guentheri. [ Conclusion] Rana guentheri in Zhaoqing area had obvious sexual dimor- phism.
基金Supported by the National Natural Science Foundation of China(No.31202001)the Natural Science Foundation of Shandong Province,China(No.ZR2012CQ010)
文摘Guppies( Poecilia reticulata) are considered a candidate model species for the identification and testing of endocrine-disrupting chemicals. Male guppies may be used to address the challenge of making potential linkages between alterations of biomarkers, both at the cellular and organ level, and adverse outcomes. In the present study, a predictive relationship between sex characteristics and reproductive output was observed in male guppies that underwent a long-term toxicity test with 0.5 μg/L 17 β-estradiol administered during the juvenile period. Radioimmunoassay and western blot analyses demonstrated that 17 β-estradiol exposure caused a significant increase in testicular 17 β-estradiol levels as well as the induction of exposure biomarkers, namely hepatic vitellogenin. Exposure to 17 β-estradiol also caused a significant decrease in testosterone levels, which consequently reduced the gonadosomatic index, sperm counts, and the coloration index. These changes of male sexual characteristics further translated into adverse influences on reproduction, as measured by a decrease in offspring production and survival rate. Our results suggest that the above-mentioned sexual characteristics of male guppies may be considered potential in vivo biomarkers of estrogen effects on reproduction.
基金supported by the National Natural Science Foundation of China (31260518 to JW)the Education Department of Hainan Province (00501023523)
文摘Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Polypedates megacephalus and P. mutus are two sympatric and morphologically similar tree frogs, but it remains unknown whether their calls are associated with body size. In this study, we compared call characteristics of these two species and investigated any potential relationships with body size. We found that P. megacephalus, males produced six call types which consisting of three distinct notes, while P. mutus males produced five types consisting of two types of notes. Dominant frequency, note duration, pulse duration, and call duration exhibited significant interspecific differences. In P. megacephalus, one note exhibited a dominant frequency that was negatively correlated with body mass, snout-vent length, head length, and head width. In P. mutus, the duration of one note type was positively correlated with body mass and head width. These differences in call characteristics may play an important role in interspecific recognition. Additionally, because interspecific acoustic variation reflects body size, calls may be relevant for sexual selection. Taken together, our results confirmed that calls are a valid tool for distinguishing between the two tree-frog species in the field.
文摘This study evaluates variables concerning demographic characteristics for all adult male offenders convicted of Child Sexual Abuse(CSA)aged 0–17 in Malmö,Sweden between 2013 and 2018.All convictions(n=18)based on court documents from the District Court,the Court of Appeals and information from the Swedish Tax Agency were reviewed.A total of 30 victims were identified.Frequency analyses show that the most common features were that of a single offender,averaging 25 years old,with a non-Swedish background and a high school degree.The predominately extrafamilial CSA(i.e.committed by an acquaintance to the family)occurred in a private setting and consisted of penetrative acts.Girls averaging 13years old were abused multiple times,under fear and pressure.Although assumptions based on these results are preliminary,they provide a clearer image of the typical circumstances under which CSA occurred within this time frame and geographical location.This study is a first attempt to construct an overview of demographic characteristics of CSA.As more data are gathered from this region,more sophisticated analyses can be conducted,providing stronger generalizations.Information of this kind may be important for research,classification of offender profiling and in case linking.