While the ecological impacts of invasive species have been demonstrated for many taxonomic groups, the potential effects of behavioural variation among nonnative individuals （i.e. personality） on these impacts have ...While the ecological impacts of invasive species have been demonstrated for many taxonomic groups, the potential effects of behavioural variation among nonnative individuals （i.e. personality） on these impacts have been largely overlooked. This is despite the fact that recent studies have demonstrated that, by nature, the three first stages of biological invasions （i.e. transport, establishment and spread） can lead to personalitybiased populations. Freshwater ecosystems provide a unique oppor tunity to investigate this issue, notably because the ecological impacts of nonnative species have been extensively documented and because animal personality has been widely studied using freshwater model species. Here, we aim at developing some per spectives on the potential effects of animal personality on the ecological impacts of freshwater nonnative species across levels of biological organizations. At the individual level, personality types have been demonstrated to affect the physiolo gy, metabolism, life history traits and fitness of individuals. We used these effects to discuss how they could subsequently impact invaded popula tions and, in turn, recipient communities. We also discussed how these might translate into changes in the structure of food webs and the functioning of invaded ecosystems. Finally we discussed how these perspectives could interact with the management of invasive species .展开更多
The hydrogen peroxide, a green impregnating agent suitable for lignocellulosic biomass to bioethanol process, was used to pretreat sugarcane bagasse by steam explosion. Two different concentrations of hydrogen peroxid...The hydrogen peroxide, a green impregnating agent suitable for lignocellulosic biomass to bioethanol process, was used to pretreat sugarcane bagasse by steam explosion. Two different concentrations of hydrogen peroxide（0.2% and 1%） were investigated. Then, the biomass was hydrolyzed after pretreatment using cellulase. The amount released of：（i） cellobiose;（ii） monosaccharides, as glucose, xylose, arabinose and mannose and（iii） lignocellulose derived by-products, as furans and small organic acids（acetic, formic,and levulinic acid）, was evaluated in the hydrolysate samples, previously pretreated both in the presence and absence of impregnating agent. By adding of hydrogen peroxide in steam-pretreatment, the average yield increase was 12% for glucose and as high as 34% for xylose, and cellobiose yield was decreased of about 30%. No significant increase has been observed in arabinose and mannose yield. Furthermore,the hydrogen peroxide seems not increased the formation of lignocellulose derived by-products during pretreatment process, with the exception of the levulinic acid.展开更多
Two cornborer species, Ostrinia furnacalis （Lepidoptera： Crambidae） and O. nubilalis, are major corn pests in Asia and Europe, respectively. In both continents, the larval endoparasitoid Macrocentrus cingulum （Hym...Two cornborer species, Ostrinia furnacalis （Lepidoptera： Crambidae） and O. nubilalis, are major corn pests in Asia and Europe, respectively. In both continents, the larval endoparasitoid Macrocentrus cingulum （Hymenoptera： Braconidae） develops on another, closely related stemborer, O. scapulalis, which feeds on mugwort and other dicotyledons. M. cingulum also emerges from O. furnacalis in Asia and （9. nubilalis in North America, but not from O. nubilalis in Europe. We assessed the ability of three populations of each of the three Ostrinia species to encapsulate foreign bodies of a size similar to that of a M. cingulum egg. We conclude that variations in encapsulation ability alone cannot account for the differences observed in the field between parasite emergence rates in these different host species and geographic areas.展开更多
Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional conte...Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional content, toxicity and digestibility as well as their role in the shaping of bee-flower interactions have been poorly studied. In this study we combined bioassays of the generalist bee Bombus terrestris on pollen of Cirsium, Trifolium, Salix, and Cistus genera with an assessment of nutritional content, toxicity, and digestibility of pollen. Microcolonies showed significant differences in their development, non-host pollen of Cirsium being the most unfavorable. This pollen was characterized by the presence of quite rare 37-sterols and a low digestibility. Cirsium consumption seemed increase syrup collection, which is probably related to a detoxification mixing behavior. These results strongly suggest that pollen traits may act as drivers of plant selection by bees and partly explain why Asteraceae pollen is rare in bee generalist diet.展开更多
文摘While the ecological impacts of invasive species have been demonstrated for many taxonomic groups, the potential effects of behavioural variation among nonnative individuals （i.e. personality） on these impacts have been largely overlooked. This is despite the fact that recent studies have demonstrated that, by nature, the three first stages of biological invasions （i.e. transport, establishment and spread） can lead to personalitybiased populations. Freshwater ecosystems provide a unique oppor tunity to investigate this issue, notably because the ecological impacts of nonnative species have been extensively documented and because animal personality has been widely studied using freshwater model species. Here, we aim at developing some per spectives on the potential effects of animal personality on the ecological impacts of freshwater nonnative species across levels of biological organizations. At the individual level, personality types have been demonstrated to affect the physiolo gy, metabolism, life history traits and fitness of individuals. We used these effects to discuss how they could subsequently impact invaded popula tions and, in turn, recipient communities. We also discussed how these might translate into changes in the structure of food webs and the functioning of invaded ecosystems. Finally we discussed how these perspectives could interact with the management of invasive species .
文摘The hydrogen peroxide, a green impregnating agent suitable for lignocellulosic biomass to bioethanol process, was used to pretreat sugarcane bagasse by steam explosion. Two different concentrations of hydrogen peroxide（0.2% and 1%） were investigated. Then, the biomass was hydrolyzed after pretreatment using cellulase. The amount released of：（i） cellobiose;（ii） monosaccharides, as glucose, xylose, arabinose and mannose and（iii） lignocellulose derived by-products, as furans and small organic acids（acetic, formic,and levulinic acid）, was evaluated in the hydrolysate samples, previously pretreated both in the presence and absence of impregnating agent. By adding of hydrogen peroxide in steam-pretreatment, the average yield increase was 12% for glucose and as high as 34% for xylose, and cellobiose yield was decreased of about 30%. No significant increase has been observed in arabinose and mannose yield. Furthermore,the hydrogen peroxide seems not increased the formation of lignocellulose derived by-products during pretreatment process, with the exception of the levulinic acid.
文摘Two cornborer species, Ostrinia furnacalis （Lepidoptera： Crambidae） and O. nubilalis, are major corn pests in Asia and Europe, respectively. In both continents, the larval endoparasitoid Macrocentrus cingulum （Hymenoptera： Braconidae） develops on another, closely related stemborer, O. scapulalis, which feeds on mugwort and other dicotyledons. M. cingulum also emerges from O. furnacalis in Asia and （9. nubilalis in North America, but not from O. nubilalis in Europe. We assessed the ability of three populations of each of the three Ostrinia species to encapsulate foreign bodies of a size similar to that of a M. cingulum egg. We conclude that variations in encapsulation ability alone cannot account for the differences observed in the field between parasite emergence rates in these different host species and geographic areas.
文摘Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional content, toxicity and digestibility as well as their role in the shaping of bee-flower interactions have been poorly studied. In this study we combined bioassays of the generalist bee Bombus terrestris on pollen of Cirsium, Trifolium, Salix, and Cistus genera with an assessment of nutritional content, toxicity, and digestibility of pollen. Microcolonies showed significant differences in their development, non-host pollen of Cirsium being the most unfavorable. This pollen was characterized by the presence of quite rare 37-sterols and a low digestibility. Cirsium consumption seemed increase syrup collection, which is probably related to a detoxification mixing behavior. These results strongly suggest that pollen traits may act as drivers of plant selection by bees and partly explain why Asteraceae pollen is rare in bee generalist diet.
