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您的检索式：作者名="Josh Baker"
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| 1 | The role of phosphorus in the metabolism of arsenate by a freshwater green alga, Chlorella vulgaris显示文摘A freshwater microalga, Chlorella vulgaris, was grown in the presence of varying phosphate concentrations(< 10–500 μg/L P) and environmentally realistic concentrations of arsenate(As(Ⅴ))(5–50 μg/L As). Arsenic speciation in the culture medium and total cellular arsenic were measured using AEC-ICP-MS and ICP-DRC-MS, respectively, to determine arsenic biotransformation and uptake in the various phosphorus scenarios. At high phosphate concentration in the culture medium, > 100 μg/L P, the uptake and biotransformation of As(Ⅴ) was minimal and dimethylarsonate(DMAs(Ⅴ)) was the dominant metabolite excreted by C. vulgaris, albeit at relatively low concentrations. At common environmental P concentrations, 0–50 μg/L P, the uptake and biotransformation of As(Ⅴ) increased. At these higher As-uptake levels, arsenite(As(Ⅲ)) was the predominant metabolite excreted from the cell. The concentrations of As(Ⅲ) in these low P conditions were much higher than the concentrations of methylated arsenicals observed at the various P concentrations studied. The switchover threshold between the(small) methylation and(large) reduction of As(Ⅴ) occurred around a cellular As concentration of 1 fg/cell. The observed nearly quantitative conversion of As(Ⅴ) to As(Ⅲ) under low phosphate conditions indicates the importance of As(Ⅴ) bio-reduction at common freshwater P concentrations. These findings on the influence of phosphorus on arsenic uptake, accumulation and excretion are discussed in relation to previously published research. The impact that the two scenarios of As(Ⅴ) metabolism, As(Ⅲ) excretion at high As(Ⅴ)-uptake and methylarsenical excretion at low As(Ⅴ)-uptake, have on freshwater arsenic speciation is discussed. | Josh Baker Dirk Wallschlager | 2016 | Journal of Environmental Sciences2016，28，11： | 7 |
| 2 | OpenAI发布训练实体机器人的最新模拟环境显示文摘最近,OpenAI发布了8个模拟机器人环境,以及一个事后经验回放(Hindsight Experience Replay)的基线实现,所有这些都是基于过去一年的研究而开发,并已经使用这些环境对在物理机器人上运行的模型进行训练。同时,OpenAI还发布了一系列用于机器人研究的请求。 | MATTHIAS PLAPPERT MARCIN ANDRYCHOWICZ ALEX RAY BOB MCGREW BOWEN BAKER GLENN POWELL JONAS SCHNEIDER JOSH TOBIN MACIEK CHOQEJ PETER WELINDER VIKASH KUMAR WOJCIECH ZAREMBA | 2018 | 机器人产业2018，，2： | 1 |
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