Most plastics are released into the environment once they are discarded,resulting in microplastics(<5 mm)being found in every part of the world.To better understand their toxicity,we exposed four generations of the...Most plastics are released into the environment once they are discarded,resulting in microplastics(<5 mm)being found in every part of the world.To better understand their toxicity,we exposed four generations of the fruit fly,Drosophila melanogaster,to high-density polyethylene(HDPE)microplastics(<38μm)and monitored their reproductive performance.We found that the eclosion fraction of pupae was 5.7%higher(p<0.05)in the stream of flies that were fed 100 mg/kg HDPE across all generations when compared to those fed control food.Several fourth-generation treatment flies expressed malformed salivary glands and scutella.No toxicity was observed in the number of pupae and flies that emerged from the eggs laid in each generation or their mean pupation and eclosion time.Moreover,no toxicity was observed in the development of larvae into adult flies(0.1−10000 mg/kg HDPE)and various sublethal end points(100 mg/kg HDPE)such as larva and adult fly locomotion and the mass of female and male flies.These results,obtained with realistic weathered microplastics,indicate that HDPE microplastics at the concentrations evaluated are unlikely to be lethal in Drosophila melanogaster;however malformations are still possible despite little-to-no observable internalization of the microplastics.展开更多
Lateritic soils are frequently utilised in tropical areas of the developing world as an engineering material in the construction of rural earth roads, usually in the form of engineered natural surface (ENS) roads. The...Lateritic soils are frequently utilised in tropical areas of the developing world as an engineering material in the construction of rural earth roads, usually in the form of engineered natural surface (ENS) roads. The heavy, seasonal rainfalls common to the tropics results in ENS roads becoming quickly saturated with rainwater, and no longer accessible to motorised transportation. Microbially induced calcite precipitation (MICP) has been successfully used as a treatment process to decrease the permeability of clean, cohesionless sands by studies trying to impede the movement of groundwater, and any pollutants they may contain. In order to see if MICP treatment can also reduce the susceptibility of ENS road lateritic soils to rainwater saturation, this study has treated a Brazilian sample extracted from an ENS road in Espirito do Santo, Brazil, using the MICP bacterium Sporosarcina pasteurii contained within a urea-calcium chloride solution inoculum. Investigation, by means of a Rowe cell, of the post-treatment permeability, to untreated control samples, has shown an average decrease in the vertical coefficient of permeability of 83%, from 1.15 × 10-7 m/s for the untreated control samples, to 1.92 × 10-8 m/s in treated samples.展开更多
"My Electric Avenue"开拓性项目设立的目的是用来评估未来插电式电动车被大量使用时,其对区域供电系统会带来怎样的影响。可能有一些关于电动汽车取得重要发展的疑问:早期的使用者正转变为回头客,大量依赖个人传输能源或者..."My Electric Avenue"开拓性项目设立的目的是用来评估未来插电式电动车被大量使用时,其对区域供电系统会带来怎样的影响。可能有一些关于电动汽车取得重要发展的疑问:早期的使用者正转变为回头客,大量依赖个人传输能源或者完全用电能来取代汽油柴油的概念正大行其道。举个例子,英国在2年前仅有3500辆插电式电动车的登记量,而201 5年单年就有接近4.8万辆插电式电动车被登记上牌。随着消费者能够在38种不同的插电式电动车和纯电动车中进行选择,如今英国所有新车登记中已经有1.7%为插电式电动车。展开更多
基金support from the Natural Sciences and Engineering Research Council of Canada(NSERC)for the Discovery,Strategic,and PURE CREATE programs,the Canada Research Chairs Program,the Killam Research Fellowship,the Canada Foundation for Innovation,the FRQNT.S.Chahal acknowledges NSERC for a PGS D scholarship,McGill University for a MEDA fellowship,the support of the EUL fund in the Department of Chemical EngineeringEcotoQ.J.-R.M acknowledges NSERC and FRQNT for a Postdoctoral Fellowship.
文摘Most plastics are released into the environment once they are discarded,resulting in microplastics(<5 mm)being found in every part of the world.To better understand their toxicity,we exposed four generations of the fruit fly,Drosophila melanogaster,to high-density polyethylene(HDPE)microplastics(<38μm)and monitored their reproductive performance.We found that the eclosion fraction of pupae was 5.7%higher(p<0.05)in the stream of flies that were fed 100 mg/kg HDPE across all generations when compared to those fed control food.Several fourth-generation treatment flies expressed malformed salivary glands and scutella.No toxicity was observed in the number of pupae and flies that emerged from the eggs laid in each generation or their mean pupation and eclosion time.Moreover,no toxicity was observed in the development of larvae into adult flies(0.1−10000 mg/kg HDPE)and various sublethal end points(100 mg/kg HDPE)such as larva and adult fly locomotion and the mass of female and male flies.These results,obtained with realistic weathered microplastics,indicate that HDPE microplastics at the concentrations evaluated are unlikely to be lethal in Drosophila melanogaster;however malformations are still possible despite little-to-no observable internalization of the microplastics.
文摘Lateritic soils are frequently utilised in tropical areas of the developing world as an engineering material in the construction of rural earth roads, usually in the form of engineered natural surface (ENS) roads. The heavy, seasonal rainfalls common to the tropics results in ENS roads becoming quickly saturated with rainwater, and no longer accessible to motorised transportation. Microbially induced calcite precipitation (MICP) has been successfully used as a treatment process to decrease the permeability of clean, cohesionless sands by studies trying to impede the movement of groundwater, and any pollutants they may contain. In order to see if MICP treatment can also reduce the susceptibility of ENS road lateritic soils to rainwater saturation, this study has treated a Brazilian sample extracted from an ENS road in Espirito do Santo, Brazil, using the MICP bacterium Sporosarcina pasteurii contained within a urea-calcium chloride solution inoculum. Investigation, by means of a Rowe cell, of the post-treatment permeability, to untreated control samples, has shown an average decrease in the vertical coefficient of permeability of 83%, from 1.15 × 10-7 m/s for the untreated control samples, to 1.92 × 10-8 m/s in treated samples.
文摘"My Electric Avenue"开拓性项目设立的目的是用来评估未来插电式电动车被大量使用时,其对区域供电系统会带来怎样的影响。可能有一些关于电动汽车取得重要发展的疑问:早期的使用者正转变为回头客,大量依赖个人传输能源或者完全用电能来取代汽油柴油的概念正大行其道。举个例子,英国在2年前仅有3500辆插电式电动车的登记量,而201 5年单年就有接近4.8万辆插电式电动车被登记上牌。随着消费者能够在38种不同的插电式电动车和纯电动车中进行选择,如今英国所有新车登记中已经有1.7%为插电式电动车。
