Objective:To assess the molluscicidal and cercariacidal activities of aqueous extracts of Balanites aegyptiaca(B.aegyptiaca)against EthiopianBiomphalaria pfeifferi(B.pfeifferi),Lymnaea natalensis(L.natalensis)and Schi...Objective:To assess the molluscicidal and cercariacidal activities of aqueous extracts of Balanites aegyptiaca(B.aegyptiaca)against EthiopianBiomphalaria pfeifferi(B.pfeifferi),Lymnaea natalensis(L.natalensis)and Schistosoma mansoni(S.mansoni)cercariae.Methods:Extracts of seeds,endocarp,mesocarp,and fruit of B.aegyptiacawere tested for their activities against adultB.pfeifferiandL.natalensis.The cercariacidal activity of the seeds of the plant was also evaluated againstS.mansoni.Bioassays were carried out following the methods recommended by WHO.Snail mortalities were compared between each plant part and snail species,and LC50and LC90values for the plant parts tested were computed.The cercariacidal activity of the plant was assessed by exposing the mice to the cercariae pre-exposed to aqueous extract of B.aegyptiacaseeds.Results:For the molluscicidal activities of seeds,endocarp,mesocarp and whole fruit,the LC50values againstB.pfeifferiwere 56.32,77.53,65.51 and 66.63 mg/L,respectively,while the respective LC90values were 77.70,120.04,89.50 and 97.55 mg/L.Similarly,the LC50values for the seeds,endocarp,mesocarp and whole fruit againstL.natalensiswere 80.33,92.61,83.52 and 87.84mg/L,respectively,while the respective LC90values were 102.30,138.21,115.42 and 127.69 mg/L.B.pfeifferiwere found to be more susceptible toB.aegyptiacathanL.natalensis.S.mansoni cercariae exposed to 15 mg/L of extract of seeds were incapable of infecting mice.The mean egg load of tissue was reduced in mice infected with the cercariae exposed to 5 and 10 mg/L of the extract.Conclusions:The aqueous extracts of different parts ofB.aegyptiacaexhibited reasonable molluscicidal activity againstB.pfeifferiandL.natalensis,as well as cercariacidal activity againstS.mansonicercariae.However,comprehensive laboratory evaluation is recommended prior to field tests of the plant parts since their impact on other aquatic biota is not known.展开更多
Consistent among individual variation in behavior,or animal personality,is present in a wide variety of species.This behavioral variation is maintained by both genetic and environmental factors.Parental effects are a ...Consistent among individual variation in behavior,or animal personality,is present in a wide variety of species.This behavioral variation is maintained by both genetic and environmental factors.Parental effects are a special case of environmental variation and are expected to evolve in populations experiencing large fluctuations in their environment.They represent a non-genetic pathway by which parents can transmit information to their offspring,by modulating their personality.While it is expected that parental effects contribute to the observed personality variation,this has rarely been studied in wild populations.We used the multimammate mouse Mastomys natalensis as a model system to investigate the potential effects of maternal personality on offspring behavior.We did this by repeatedly recording the behavior of individually housed juveniles which were born and raised in the lab from wild caught females.A linear correlation,between mother and offspring in behavior,would be expected when the personality is only affected by additive genetic variation,while a more complex relationship would suggests the presence of maternal effects.We found that the personality of the mother predicted the behavior of their offspring in a non-linear pattern.Exploration behavior of mother and offspring was positively correlated,but only for slow and average exploring mothers,while this correlation became negative for fast exploring mothers.This may suggests that early maternal effects could affect personality in juvenile M.natalensis,potentially due to density-dependent and negative frequency-dependent mechanisms,and therefore contribute to the maintenance of personality variation.展开更多
基金Financially supported by School of Graduate Studies,Addis Ababa University(Grant No.GSR/2830/02)
文摘Objective:To assess the molluscicidal and cercariacidal activities of aqueous extracts of Balanites aegyptiaca(B.aegyptiaca)against EthiopianBiomphalaria pfeifferi(B.pfeifferi),Lymnaea natalensis(L.natalensis)and Schistosoma mansoni(S.mansoni)cercariae.Methods:Extracts of seeds,endocarp,mesocarp,and fruit of B.aegyptiacawere tested for their activities against adultB.pfeifferiandL.natalensis.The cercariacidal activity of the seeds of the plant was also evaluated againstS.mansoni.Bioassays were carried out following the methods recommended by WHO.Snail mortalities were compared between each plant part and snail species,and LC50and LC90values for the plant parts tested were computed.The cercariacidal activity of the plant was assessed by exposing the mice to the cercariae pre-exposed to aqueous extract of B.aegyptiacaseeds.Results:For the molluscicidal activities of seeds,endocarp,mesocarp and whole fruit,the LC50values againstB.pfeifferiwere 56.32,77.53,65.51 and 66.63 mg/L,respectively,while the respective LC90values were 77.70,120.04,89.50 and 97.55 mg/L.Similarly,the LC50values for the seeds,endocarp,mesocarp and whole fruit againstL.natalensiswere 80.33,92.61,83.52 and 87.84mg/L,respectively,while the respective LC90values were 102.30,138.21,115.42 and 127.69 mg/L.B.pfeifferiwere found to be more susceptible toB.aegyptiacathanL.natalensis.S.mansoni cercariae exposed to 15 mg/L of extract of seeds were incapable of infecting mice.The mean egg load of tissue was reduced in mice infected with the cercariae exposed to 5 and 10 mg/L of the extract.Conclusions:The aqueous extracts of different parts ofB.aegyptiacaexhibited reasonable molluscicidal activity againstB.pfeifferiandL.natalensis,as well as cercariacidal activity againstS.mansonicercariae.However,comprehensive laboratory evaluation is recommended prior to field tests of the plant parts since their impact on other aquatic biota is not known.
基金B.V.B.was funded by the Ph.D.fellowship from the Research Foundation Flanders(FWO)(grant ID:11A0817N).
文摘Consistent among individual variation in behavior,or animal personality,is present in a wide variety of species.This behavioral variation is maintained by both genetic and environmental factors.Parental effects are a special case of environmental variation and are expected to evolve in populations experiencing large fluctuations in their environment.They represent a non-genetic pathway by which parents can transmit information to their offspring,by modulating their personality.While it is expected that parental effects contribute to the observed personality variation,this has rarely been studied in wild populations.We used the multimammate mouse Mastomys natalensis as a model system to investigate the potential effects of maternal personality on offspring behavior.We did this by repeatedly recording the behavior of individually housed juveniles which were born and raised in the lab from wild caught females.A linear correlation,between mother and offspring in behavior,would be expected when the personality is only affected by additive genetic variation,while a more complex relationship would suggests the presence of maternal effects.We found that the personality of the mother predicted the behavior of their offspring in a non-linear pattern.Exploration behavior of mother and offspring was positively correlated,but only for slow and average exploring mothers,while this correlation became negative for fast exploring mothers.This may suggests that early maternal effects could affect personality in juvenile M.natalensis,potentially due to density-dependent and negative frequency-dependent mechanisms,and therefore contribute to the maintenance of personality variation.
