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Volatile Organic Compounds in Alberta, Canada Residences—Evidence from Community Surveys

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Journal of Environmental Protection 2012年第9期3卷 1176-1187页

作者： warren Kindzierski Department of Public Health Sciences School of Public Health Edmonton Canada

The impact of the built environment on public health is complex, involving several determinants of health including indoor air quality. People who spend the most time indoors can be exposed to indoor air pollutants for long periods of time. These are often the same people who are most susceptible to adverse effects if exposures are high enough (young children, elderly, and chronically ill, especially those suffering from respiratory diseases). An analysis of data on selected indoor volatile organic compounds (VOCs) from community studies in Alberta, Canada was undertaken. Measures of typical (central tendency) and high end (upper limit) indoor concentrations were estimated from seven studies in Alberta. Best estimates of central tendency indoor concentrations for 12 VOCs—benzene, ethylbenzene, o-xylene, 3-methylhexane, heptane, octane, nonane, decane, 1,1,1-trichloroethane, carbon tetrachloride, tetrachloroethylene, and 1,2,4-trimethylbenzene—were less than 5 μg/m3. Best estimates of central tendency indoor concentrations for three VOCs—toluene, m/p-xylene, and limonene—were greater than 5 μg/m3. In the case of best estimates of upper limit indoor concentrations—benzene, ethylbenzene, o-xylene, hexane, 3-methylhexane, heptane, octane, nonane, carbon tetrachloride, and tetrachloroethylene had upper limit concentrations less than 15 μg/m3. Best estimates of upper limit indoor concentrations for toluene, m/p xylene, decane, limonene, 1,1,1-trichloroethane, and 1,2,4-trimethylbenzene were greater than 15 μg/m3. Upper limit concentrations observed inside Alberta residences were about 4 to 10 times higher than typical concentrations for most of the VOCs observed. Upper limit indoor concentrations for carbon tetrachloride and benzene in Alberta are similar to or greater than levels judged by US EPA to imply a concern for potential cancer effects. This indicates that some homes in Alberta can have levels of carbon tetrachloride and benzene that may be of concern from a publ

关键词： VOCs Air Quality Indoor Air Alberta

Accommodating the bacterial decoding release factor as an alien protein among the RNAs at the active site of the ribosome

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Cell Research 2007年第7期17卷 591-607页

作者： Elizabeth S Poole David J Young Marjan E Askarian-Amiri Debbie-Jane G Scarlett warren P Tate Department of Biochemistry University of OtagoP.O.Box 56 DunedinNew Zealand

The decoding release factor (RF) triggers termination of protein synthesis by functionally mimicking a tRNA to spanthe decoding centre and the peptidyl transferase centre (PTC) of the ribosome. Structurally, it must fit into a site craftedfor a tRNA and surrounded by five other RNAs, namely the adjacent peptidyl tRNA carrying the completed polypeptide,the mRNA and the three rRNAs. This is achieved by extending a structural domain from the body of the protein thatresults in a critical conformational change allowing it to contact the PTC. A structural model of the bacterial terminationcomplex with the accommodated RF shows that it makes close contact with the first, second and third bases of the stopcodon in the mRNA with two separate loops of structure: the anticodon loop and the loop at the tip of helix α5. Theanticodon loop also makes contact with the base following the stop codon that is known to strongly influence termina-tion efficiency. It confirms the close contact of domain 3 of the protein with the key RNA structures of the PTC. ThemRNA signal for termination includes sequences upstream as well as downstream of the stop codon, and this may reflectstructural restrictions for specific combinations of tRNA and RF to be bound onto the ribosome together. An unbiasedSELEX approach has been investigated as a tool to identify potential rRNA-binding contacts of the bacterial RF in itsdifferent binding conformations within the active centre of the ribosome.

关键词： release factor protein synthesis termination tRNA functional mimicry molecular mimicry SELEX ribosome

The Greenhouse Effect: An Evaluation of Arrhenius’ Thesis and a New Energy Equilibrium Model

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Natural Science 2018年第1期10卷 1-10页

作者： warren Stannard School of Physics University of Western Australia Crawley Australia

In 1896, Svante Arrhenius proposed a model predicting that increased concentration of carbon dioxide and water vapour in the atmosphere would result in a warming of the planet. In his model, the warming effects of atmospheric carbon dioxide and water vapour in preventing heat flow from the Earth’ s surface (now known as the “Greenhouse Effect”)?are?counteracted by a cooling effect where the same gasses are responsible for the radiation of heat to space from the atmosphere. His analysis found that there was a net warming effect and his model has remained the foundation of the Enhanced Greenhouse Effect—Global Warming hypothesis. This paper attempts to quantify the parameters in his equations but on evaluation his model cannot produce thermodynamic equilibrium. A modified model is proposed which reveals that increased atmospheric emissivity enhances the ability of the atmosphere to radiate heat to space overcoming the cooling effect resulting in a net cooling of the planet. In consideration of this result, there is a need for greenhouse effect—global warming models to be revised.

关键词： Greenhouse Effect Atmospheric Physics Energy Budget Arrhenius Greenhouse Gases

New contributions to the phylogeny of the ciliate class Heterotrichea(Protista,Ciliophora):analyses at family-genus level and new evolutionary hypotheses

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Science China(Life Sciences) 2021年第4期64卷 606-620页

作者： Yong Chi Xiangrui Chen Yuqing Li Chundi Wang Tengteng Zhang Alex Ayoub Alan warren Weibo Song Yuanyuan Wang Instiue of Evoluion&Marine Biodiversity and College of Fisheries Ocean University of ChinaQingdao 266003China School of Marine Sciences Ningbo University Ningbo 315211China Department of Pathology University of MichiganAnn Arbor M148109USA Deparmen of Life Sciences Narural Histony MuseumLondon SW75BDUK Laboratory for Marine Biology&Biotechnologr.Qingdao National Laboratory for Marine Science and TechnologyQingdao 266003China College of Marine Life Sciences Ocean Universiy of ChinaQingdao 266003.China

Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and *** the present study,we combine both morphological and molecular data to infer phylogenetic relationships at family-genus level and propose new evolutionary hypotheses for the class *** main results include:(1)96 new ribosomal DNA sequences from 36 populations,representing eight families and 13 genera,including three poorly annotated genera,Folliculinopsis,Ampullofolliculina and Linostomella;(2)the earliest-branching families are Spirostomidae in single-gene trees and Peritromidae in the concatenated tree,but the family Peritromidae probably represents the basal lineage based on its possession of many"primitive"morphological characters;(3)some findings in molecular trees are not supported by morphological evidence,such as the family Blepharismidae is one of the most recent branches and the relationship between Fabreidae and Folliculinidae is very close;(4)the systematic positions of Condylostomatidae,Climacostomidae,and Gruberiidae remain uncertain based either on morphological or molecular data;and(5)the monophyly of each genus included in the present study is supported by the molecular phylogenetic trees,except for Blepharisma in the SSU r DNA tree and Folliculina in the ITS1-5.8 S-ITS2 tree.

关键词： evolutionary hypothesis molecular cladogram morphological cladogram multi-gene systematic relationship

ExaHDF5: Delivering Efficient Parallel I/O on Exascale Computing Systems

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Journal of Computer Science & Technology 2020年第1期35卷 145-160页

作者： Suren Byna M.Scot Breitenfeld Bin Dong Quincey Koziol Elena Pourmal Dana Robinson Jerome Soumagne Houjun Tang Venkatram Vishwanath Richard warren Lawrence Berkeley National Laboratory BerkeleyCA 94597U.S.A The HDF Group ChampaignIL 61820U.S.A Argonne National Laboratory LemontIL 60439U.S.A

Scientific applications at exascale generate and analyze massive amounts of data.A critical requirement of these applications is the capability to access and manage this data efficiently on exascale *** I/O,the key technology enables moving data between compute nodes and storage,faces monumental challenges from new applications,memory,and storage architectures considered in the designs of exascale *** the storage hierarchy is expanding to include node-local persistent memory,burst buffers,etc.,as well as disk-based storage,data movement among these layers must be *** I/O libraries of the future should be capable of handling file sizes of many terabytes and *** this paper,we describe new capabilities we have developed in Hierarchical Data Format version 5(HDF5),the most popular parallel I/O library for scientific ***5 is one of the most used libraries at the leadership computing facilities for performing parallel I/O on existing HPC *** state-of-the-art features we describe include:Virtual Object Layer(VOL),Data Elevator,asynchronous I/O,full-featured single-writer and multiple-reader(Full SWMR),and parallel *** this paper,we introduce these features,their implementations,and the performance and feature benefits to applications and other libraries.

关键词： parallel I/O Hierarchical Data Format version 5(HDF5) I/O performance virtual object layer HDF5 optimizations

血管内皮干细胞动员剂对糖尿病小鼠颅骨缺损愈合的影响

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中华整形外科杂志 2011年第6期27卷 442-447页

作者：王晓霞 Stephen warren 北京大学口腔医院口腔颌面外科北京100086 纽约大学医学中心整形与重建外科研究所

目的探讨血管内皮干细胞（endothelial pregenitor cell，EPC）动员剂AMD3100对糖尿病小鼠颅骨缺损愈合的影响。方法2型糖尿病小鼠55只，随机分为未手术组（n=5）、实验组（n=25）和对照组（n=25）。实验组和对照组均在其颅骨表面制造2... 详细信息

目的探讨血管内皮干细胞（endothelial pregenitor cell，EPC）动员剂AMD3100对糖尿病小鼠颅骨缺损愈合的影响。方法2型糖尿病小鼠55只，随机分为未手术组（n=5）、实验组（n=25）和对照组（n=25）。实验组和对照组均在其颅骨表面制造2个直径3mm圆形骨缺损，实验组于术后第3天起给予AMD3100腹腔注射，每日10mg／kg，共15d，对照组给予生理盐水腹腔注射。未手术组处死5只小鼠，实验组和对照组分别于术后1、2、4、8、12周时处死5只小鼠，取外周血测量术前及术后7、14d小鼠血液EPC含量；取颅骨标本，对术后第4、8、12周标本行micro—CT检查，测量计算骨缺损愈合百分比；对所有标本的脱钙石蜡切片进行HE染色，对术后第1、2、4周标本的冰冻切片行CD31和骨钙素免疫荧光染色，计算成骨区血管密度和成骨细胞密度。采用t检验对数据进行统计学分析。结果糖尿病小鼠EPC的动员在创伤后1周基本消失，而AMD3100可显著增高创伤后期血液中EPC水平。AMD3100治疗的糖尿病小鼠在术后第8周和第12周时其骨缺损愈合百分比分别为50．5％、50．9％，均高于对照组的34．8％、40．2％，差异具有统计学意义（P〈0．05）；实验组成骨区血管密度和成骨细胞密度在术后1、2、4周均较对照组增加2倍左右，以术后第2周最显著（实验组毛细血管密度2．47％，成骨细胞密度1．22％；对照组分别是6．11％、2．81％）。结论AMD3100可通过增加成骨区血管密度和成骨细胞密度而改善糖尿病小鼠颅骨缺损愈合程度。

关键词：血管内皮干细胞骨愈合 AMD3100 小鼠肥胖

Strongest Proof Yet of Water Flow on Mars

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科技英语学习 2007年第2期 7-9页

作者： warren Leary 陈静

近年来的试验表明,火星的地表下存在冰和水汽,这有力地证明了火星上水源的存在。美国国家航空和航天局火星研究太空船在对火星进行10年观察之后,又发现了火山壁上的两个沟槽里有些颜色很浅的沉淀物。科学家推测,这些沉淀物是由水及其它... 详细信息

近年来的试验表明,火星的地表下存在冰和水汽,这有力地证明了火星上水源的存在。美国国家航空和航天局火星研究太空船在对火星进行10年观察之后,又发现了火山壁上的两个沟槽里有些颜色很浅的沉淀物。科学家推测,这些沉淀物是由水及其它物质经由沟槽留下的。虽然证据不是确凿无疑,但是火星上存在液态水这种可能性是令人振奋的,这对于未来太空领域的探索有着十分重要的意义,因为水可以分解成氢和氧,氢可以用作火箭的燃料,而氧可以帮助宇航员在太空呼吸。

关键词： Strongest Proof Yet of Water Flow on Mars 沉淀物

Tolerance of ciliated protozoan Paramecium bursaria (Protozoa, Ciliophora) to ammonia and nitrites

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Chinese Journal of Oceanology and Limnology 2005年第3期23卷 349-353页

作者：许恒龙宋微波路璐 warren Alan The Key Laboratory of Mariculture of the Education Ministry Ocean University of China Qingdao 266003 China Department of Biology Liaocheng University Liaocheng 252059 China Department of Zoology Natural History Museum Cromwell Road London SW7 5BD UK China

The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32x–9.51 (R2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h–LC50 value for ammonia was found to be 95.50 mg/L. A linear correla- tion between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equa- tion y=2.86x+0.89 (R2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2 862.85e-0.08x (R2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y = 127.15e-0.13x (R2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.

关键词：纤毛原生动物氨水亚硝酸盐容许量毒物学

High-throughput discovery of fluoride-ion conductors via a decoupled,dynamic,and iterative(DDI)framework

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npj Computational Materials 2022年第1期8卷 983-991页

作者： Jack D.Sundberg Daniel L.Druffel Lauren M.McRae Matthew G.Lanetti Jacob T.Pawlik Scott C.warren Department of Chemistry The University of North Carolina at Chapel HillChapel HillNC27599United States

Fluoride–ion batteries are a promising alternative to lithium–ion batteries with higher theoretical capacities and working voltages,but they have experienced limited success due to the poor ionic conductivities of known electrolytes and ***,we report a high-throughput computational screening of 9747 fluoride-containing materials in search of fluoride-ion *** a combination of empirical,lightweight DFT,and nudged elastic band(NEB)calculations,we identified>10 crystal systems with high fluoride *** applied a search strategy where calculations are performed in any order(decoupled),computational resources are reassigned based on need(dynamic),and predictive models are repeatedly updated(iterative).Unlike hierarchical searches,our decoupled,dynamic,and iterative framework(DDI)began by calculating high-quality barrier heights for fluoride-ion mobility in a large and diverse group of *** high-quality dataset provided a benchmark against which a rapid calculation method could be *** accurate method was then used to measure the barrier heights for 6797 fluoride–ion *** final dataset has allowed us to discover many fascinating,high-performance conductors and to derive the design rules that govern their *** materials will accelerate experimental research into fluoride–ion batteries,while the design rules will provide an improved foundation for understanding ionic conduction.

关键词： fluoride dynamic repeatedly