美国《科学》杂志电子版ScienceMagazine1972Vol.175No.4017-1733244
science
Experimental studies of single-event e ects induced by heavy ions qJ.Liu a,*,M.D.Hou a ,B.Q.Li a ,C.L.Liu a ,Z.G.Wang a ,S.Cheng a ,Y.M.Sun a ,Y.F.Jin a ,Y.L.Lin b ,J.R.Cai b ,S.J.Wang b ,Z.H.Ye b ,G.W.Zhu b ,H.Du b ,Q.Y.Ren b ,W.Wu b ,X.M.Mao b ,Y.Q.Sun b ,R.Guo baInstitute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,People's Republic of ChinabCenter for Space Science and Applied Research,Chinese Academy of Sciences,Beijing 100080,People's Republic of ChinaAbstractThis paper presents the results of ground-based heavy ion test of single-event e ect (SEE)vulnerability on micro-circuits used in space.We observed the dependence of upset cross-sections on the incident angle of ions in Intel 8086CPU.SEU cross-sections of various SRAMs did not depend on the stored pattern,but 031and 130transitions were completely di erent for di erent manufacturer products.Some SEE protection methods were veri®ed in conditions of ground simulation experiments.Ó2000Elsevier Science B.V.All rights reserved.PACS:61.80.Jh;85.40.VbKeywords:Single-event e ect;Heavy ion simulation;Microcircuit1.IntroductionMicrocircuits in space interact with various particles and induce a variety of physical phe-nomena known as single-event e ects (SEEs)[1±3].These e ects,including single-event upset (SEU),single-event latchup (SEL),single-event burnout (SEB),etc.,result from the charge deposited by a single particle crossing a sensitive region in the device and are functions of the amount of chargecollected at the sensitive node.SEU and SEL have been observed in space systems and all e ects have been observed and studied in ground-based simu-lations using accelerators.As microcircuits have been reduced in size and charge storage capacity,and owing to a growing interest in the use of commercial devices in space,they have become vulnerable to SEEs in the space radiation envi-ronment.Accurate estimates of its probability in microelectronics used in space systems are impor-tant for system design.The SJ-5research satellite launched in May 1999had a number of SEE investigation systems,aimed at observation of SEEs in devices and sys-tems on board.Before the satellite was launched,ground-based SEE test of microcircuits had been done which permitted characterization ofdeviceqProject supported by National Science Foundation of China(19775058)and the Chinese Academy of Sciences.*Corresponding author.Tel.:+86-931-885-4867;fax:+86-931-888-1100.E-mail address:hiam@ (J.Liu).0168-583X/00/$-see front matter Ó2000Elsevier Science B.V.All rights reserved.PII:S 0168-583X (99)01103-9susceptibility to various radiation-induced distur-bances and dynamically test the equipment [4].We especially observed the angle e ect of SEU and the dependence of upset on the stored pattern,and veri®ed the SEE protection methods.2.ExperimentalThree kinds of heavy ions delivered by the Heavy Ion Research Facility in Lanzhou (HIRFL)have been used to irradiate the microcircuits.Test ions included 132MeV oxygen,1.6GeV neon and 130MeV argon ions.O and Ne ions were con-ducted to air through a thin Ni window.Then,the devices were tested using a scattered O ion beam at 15°angle which was smaller than the h 1a 4angle of nuclear reaction between 132MeV O and Ni nu-cleus.Fig.1shows a schematic diagram of the experimental set-up of the oxygen ion test.The incident ¯ux exposed to the delidded devices was estimated from the counts of the surface-barrier detector mounted at the symmetrical point of the test device with respect to the beam.In the neon ion test,degraders had been used which lowered the primary beam energy by passing the beam through thin aluminum absorbing foils.The inci-dent Ne ion beam was monitored by an air ion-ization chamber detector and then the devices,delidded or with lid,were bombarded.The Ar ions test was done in a vacuum chamber which con-tained a gold scattering foil of 254l g/cm 2.The scattering angle was chosen to be 30°.Changing the scattering angle of the device could vary the ¯ux.Further adjustment of the ¯ux was made byadjusting the accelerator ion current.The obtained beams on the surface of devices were 34.7MeV 18O,96.0MeV 20Ne and 121.3MeV 40Ar ions.Their LETs and ranges in silicon were 5.3MeV/mg/cm 2and 23.8l m,5.3and 58.7,16.5and 29.6,respectively.Every register or memory of the device was loaded with a known pattern in the test.The computer was interfaced to the RS-232line to re-motely control start/stop commands,collect test data,and perform real time test status summary.We measured both the number of cells in which upset occurred due to ion irradiation and the ¯u-ence of the ions.From these data,the upset cross-section could be derived for each device under test.3.Results and discussion 3.1.Angle e ect of SEUFour kinds of devices,which included Intel 8086CPU,IDT 7164SRAM (with polyimide ®lm),2764EPROM and 28C64E 2PROM,were tested by 18O ion.We used self-testing single computer method and chose 3MHz clock fre-quency to test the 8086CPU chips.The single-event upset was observed only in Intel 8086CPU chips,but no latchup occurred in them.No single-event e ects were detected in other devices because di erent devices have di erent thresholds of upset or latchup.By checking the errors that occurred in Intel 8086CPU we found that four 16-bit general reg-isters and four 16-bit special registers were easy to be upset besides the running program being easily hit to ¯y.The measured SEU cross-section (CS)was determined as the ratio of number of upsets to ¯uence.Two batches of Intel 8086chips have been tested.There was about a factor of two di erence in magnitude of CS between them.Possible techniques for varying the deposited energy are di erent ion types and variation of the ion energy.However,the common practice is to vary the angle of incidence of the ion beam upon the chip during testing to provide an e ective LET given by LET eff LET a cos u ,where LET is determined by the ion type and energy and u istheFig.1.Schematic representation of the test apparatus using oxygen ions which consists of the SEE monitor system and the beam ¯uence detector.974J.Liu et al./Nucl.Instr.and Meth.in Phys.Res.B 164±165(2000)973±978angle of incidence.The angle increases the ion path length through the device,therefore increas-ing the e ective LET,LET eff .In this study,the incident angle u of the beam relative to the device board was changed from 0°to 60°by rotating the two mutually perpendicular symmetry axes of the device,i.e.,the long axis and the short axis.It also included both positive and negative rotations.The curves of upset cross-sec-tion on ion LET of rotation about the long and short axes of 8086are shown in Fig.2.Two fea-tures were observed in this ®gure.Firstly,the ab-normality of CS was observed with increasing LET eff ,i.e.,when the LET eff increased the CS de-creased instead of increasing.Secondly,there was a discrepancy in the magnitude of CS between the two axes.The devices exhibited a strong angle ef-fect in this part.These were also observed by other investigators [5]corresponding to decrease of the cross-section with the tilt angle.The ®rst mea-surements of the dependence of charge collection in diodes were reported by Campell and his co-workers [6].The collected charge in the bulk de-vices decreased with the secant of the angle.When plotted versus e ective LET,the curve actually decreased.Discontinuities were observed by Sex-ton and his coworkers [7]where three ion types were used with various incidence angles to vary the e ective LET.Considering that the concept of ef-fective LET was adopted at a time when it could be assumed that the sensitive volume was a thin large-area rectangular parallelepiped,they devel-oped a correction to the CS to account for geo-metrical e ects to high LET ions.The O ion is light and its LET in Si is low.The measured cross-sec-tion corresponds to the situation in which all ions of that LET cannot deposit enough energy to cause an upset when passing through a corner of the sensitive volume.Therefore,even though the total projected area has increased with increasing angle,the total area responsible for the upset has decreased.The projected area has to be reduced by a factor of z sin u considering the edge e ect.The e ective cross-section is [8,9]CS eff CS Âcos u Àzsin u Ywhere CS eff is the e ective cross-section after cor-rection,CS is the measured upset cross-section,and x and z are the width and depth of the sensi-tive volume,respectively.The corrected cross-sec-tion curves of CS eff versus LET eff using this equation assuming that the ratio of z /x was 0.4are also shown in Fig.2.It has been found that the CS abnormality disappears.This e ect could be ex-plained on the basis of geometry e ects.We wanted to study the di erent SEU response curve that might be obtained for a rotation about the two mutually perpendicular symmetry axes in the 8086device.As Fig.2showed,although at the same LET eff the CS eff values were di erent for di erent axes.We thought that two factors have been identi®ed as potential contributors.(1)The characteristic of the charge collection by the junction was observed to vary with angle of inci-dence when the rotation was about the short symmetry axis but not about the long axis [10].Hence,there were di erent reasons for long and short axis rotation to the change in charge col-lection.Both the position of the peak and the number of events under the peak measured at a given angle of incidence depended upon which symmetry axis of the device was chosen to be the rotation axis.These features of the devices can lead to angular dependence in charge collection or charge collection response.(2)The actual charge collection structures of the SEU-sensitive micro-junctions have shapes which are either more complicated than rectangular parallelepipeds or at least are not square.Typically,they haveoneFig.2.Measured and corrected CS of SEU versus e ective LET curves for Intel 8086CPU device about long and short axes rotation.J.Liu et al./Nucl.Instr.and Meth.in Phys.Res.B 164±165(2000)973±978975dimension which is considerably shorter than the other.In Intel8086CPU,if we considered a charge collection volume with dimensions of 5Â20Â2l m3,the correction factors to be ap-plied were0.1and0.4for long axis and short axis rotation,respectively.If we used this correction factor,the CS eff values were almost the same for the two axes.From this we can conclude that the dimension of the sensitive volume was not square in Intel8086CPU,the ratio of x/y was about1/4 with its long dimension parallel to the long axis.3.2.Dependence of upset on the stored patternWe have chosen six types of high density SRAMs as test samples which came from di erent manufacturers and with di erent capacities.In order to reveal di erences in the response to data bit``0''or``1'',we used Ne ions to test SRAM for various input patterns.Di erent patterns were put in the memories,for example,``FF''means that inputting all1in the memories,``00''all0,``55'' and``AA''half0and half1.Table1lists the upset results of the test.It also includes the statistical results of130and031 transitions.No rules about the CS values of SEU were observed when they stored di erent patterns. The SEU sensitivity for0and1was about the same value.But the probability of031and 130transitions was di erent when the half0and 1were stored in the memories.The transition of 031was larger than that of130in6116,6264 and62256SRAMs produced by HITACHI.In contrast to that,the transition of130was far larger than that of031in7164and71256 SRAMs produced by IDT.In this case,greater than90%transitions of upset were130,0state was the preference state.It appeared that the probabilities of031and130transitions de-pended on the technique of di erent manufactur-Table1The results of SEU in SRAMs for di erent patternsDevice Capacity(bits)Manufacturer a Pattern CS Â10À5cm2 031(%)130(%)5A1660.339.7 61162kÂ8HITACHI B FF250043AA9144.455.65A 2.775.524.5 62648kÂ8HITACHI B FF 1.600 4.2AA23.363.636.4FF110FF1106225632kÂ8HITACHI B00190AA14068.131.9FF1571648kÂ8IDT M0013AA200100FF187125632kÂ8IDT M0020AA197.392.7FF 3.9TC551001128kÂ8TOSHIBA B00 2.9AA 3.155.045.0a B represents commercial product and M represents military product.976J.Liu et al./Nucl.Instr.and Meth.in Phys.Res.B164±165(2000)973±978ers,especially in IDT SRAMs.It was very strange that when memories all stored0in IDT SRAMs, their upset cross-sections were not smaller than that of all1.The single bit upset sensitivity ex-hibited a strong discrepancy between the two transition types[11,12],0is much less sensitive than1.It meant that the states of the gates were not entirely symmetrical with respect to0or1 [13,14].These di erences were explained in terms of the geometrical details of the memory storage element and the nodal capacitance of the element.In the experiments we found that although the ions had the same LETs,their SEU results were di erent,the higher the energy actually deposited in the sensitive volume by the ion,the larger the CS of SEU[15].Other authors[16]also found an energy and species dependence of SEU results for a bipolar memory.Stapor et al.[17]also reported an energy in¯uence on the measured cross-section of test vehicles.All these experimental observa-tions con®rmed that LET was not the only pa-rameter to take into account for determining the sensitivity of a device,especially for modern de-vices with small sensitive volumes and low LET threshold.3.3.Protection method veri®cationThe®ve di erent space SEE research instru-ments on board SJ-5satellite were designed to probe the SEE and implement some safeguarding methods to decrease the e ects.Four types of EDAC(error detection and correction)of the system were veri®ed using Ne and Ar ions in the experiments[4].1.Two CPU Redundancy.A system with two CPU working together has been built in one cir-cuit to prepare for resisting the sudden SEE oc-curring in one of them.When errors induced by ions occurred in one of them,the system out-putted several signals to show the errors and changed the CPU's working way.The availabil-ity of this method in the system while SEE oc-curred was proven.2.Reed±Solomon Coding Correction.The RS coding is the most useful to correct the paroxys-mal error like SEU.Based on hardware and software supporting,this kind of EDAC meth-od has been set up in the computer system. When ions are bombarding it,the system de-tects and corrects the error until it run normally.3.Software Self-correction.Software self-correct-ing is a utility to build the program health to op-pose SEU.The CPU and PROM were bombarded using Ne and Ar ions.The output showed that the software self-correction was running well for program setup and handling well against SEU at®rst.But the system failed because of SEL occurred at last.4.Brainpower Controller against SEL.To avoid the SEL,the device must be in a radiation hard-ness type.In the circuit,some safeguard against SEL must be set up such as restricting current.A new brainpower controller has been installed into the space computer system to restrict the abnormal current as soon as the SEL occurred. The testing controller has been®nished and tested using Ne and Ar ions.The devices had a longer lifetime in radiation environment using this controller system.4.ConclusionSEE susceptibilities of microcircuits to radia-tion environment were tested using three kinds of heavy ions at HIRFL.The Intel8086CPU device exhibited strong angle e ects when the device was tilted along its rotation axis.This abnormality of CS versus LET eff was corrected using a geometri-cal method.The di erent responses of SEU sen-sitivity existed when a di erent axis of device was chosen as the rotation symmetry axis.So it is necessary to have much information about the structure of the device and measure the SEE vul-nerability along the two axes.In various SRAMs, we observed that their SEU cross-section did not depend on the stored pattern,but031and130 transitions were completely di erent for di erent manufacturer products.We also found an energy deposition dependence of SEU results despite the same LET value of ion.Four types of EDAC protection methods of SEE were veri®ed in the experiments,including two CPU redundancy,RS coding correction,software self-correction and brainpower controller methods.J.Liu et al./Nucl.Instr.and Meth.in Phys.Res.B164±165(2000)973±978977References[1]D.Binder,E.C.Smith,A.B.Holman,IEEE Trans.Nucl.Sci.Ns-22(1975)2675.[2]W.A.Kolasinski,J.B.Blake,J.K.Anthony,et al.,IEEETrans.Nucl.Sci.NS-26(1979)5087.[3]J.C.Pickel,IEEE Trans.Nucl.Sci.43(2)(1996)483.[4]Y.L.Lin,Z.H.Ye,G.W.Zhu,et al.,in:Proceedings of the11th Conferece on Space Science and Detection,Hainan, China,1998,p.315.[5]S.Duzellier,D.Falguere,L.Mouliere,et al.,IEEE Trans.Nucl.Sci.42(6)(1995)1797.[6]A.B.Campbell,A.R.Knudson,P.Shapiro,et al.,IEEETrans.Nucl.Sci.NS-30(1983)4486.[7]F.W.Sexton,J.S.Fu,R.A.Kohler,et al.,IEEE Trans.Nucl.Sci.36(6)(1989)2311.[8]E.L.Petersen,IEEE Trans.Nucl.Sci.39(6)(1992)1577.[9]E.L.Petersen,J.C.Pickel,E.C.Smith,et al.,IEEE Trans.Nucl.Sci.40(6)(1993)1888.[10]P.J.Mcnulty,W.J.Beauvais,R.A.Et Al Reed,IEEETrans.Nucl.Sci.39(6)(1992)1622.[11]P.Calvel,mothe,C.Barillot,et al.,IEEE Trans.Nucl.Sci.41(6)(1994)2267.[12]J.Liu,F.Ma,M.D.Hou,et al.,Nucl.Instr.and Meth.B135(1998)239.[13]G.J.Brucker,W.Chater,W.A.Kolasinski,IEEE Trans.Nucl.Sci.NS27(1980)1490.[14]F.L.Hsueh,L.S.Napoli,IEEE Trans.Nucl.Sci.NS32(6)(1985)4155.[15]J.Liu,Thesis,1999,Institute of Modern Physics,ChineseAcademy of Sciences.[16]T.L.Criswell,D.L.Oberg,J.L.Wert,et al.,IEEE Trans.Nucl.Sci.NS-34(6)(1987)1316.[17]W.J.Stapor,P.T.McDonal,A.R.Knudson,et al.,IEEETrans.Nucl.Sci.NS-35(6)(1988)1585.978J.Liu et al./Nucl.Instr.and Meth.in Phys.Res.B164±165(2000)973±978。
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Science-1972-Whittaker-54-6
Maximum
Compound 4-Biphenylcarboxylic acid Diphenic acid l-Naphthoic acid
Naphthalic acid
emission wavelength
(mm)
450 482
500-515
490 500 530 560-575 497 535 570-585 495-510
fact, material taken from the walls of laser craters yielded the electron diffraction patterns that made it possible to characterize this carbon form. Moreover, laser heating of glassy carbon produced a large number of wellformed single crystals and twins. (iii) A short-duration (- 0.05-second), 50,000-A arc between graphitic carbon electrodes produced carbon VI almost exclusively in a very small yield
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小学科学网址精选学生类：学生科技网：/中国青少年科技辅导员协会：/中国科普博览：/gb/index.html科普城首页：/《大自然探索》：/《科学世界》：/自然之友：/科普城首页：/北京昆虫网：/index1.htm江苏青少年科技教育协会：/index.htm镇海小学常识教育：/~cs/index.html中国少儿科学教育网：/回归线：/中国公众科技网：/学生科技网：/index.php缙云县青少年科技教育网：/new_page10.htm北京动物园：北京野保网：中国公众科技网：/上海科普：/广东网上科学馆：/中国科技在线：做中学介绍：/Introduce/Introduce.htm苏州科普之窗：海阔凭于跃（梦想飞）的站点：/homepage.php?id=30880北京野生动物园：/大连森林动物园：/2001news/2003fw/default.asp大眼睛科技教育网：/index.htm奇迹文库：/eprint/顺德生物学网站：/华创升达气象科普：/knowledge.htm缙云县青少年科技教育网：/new_page10.htm人民网环保频道：/GB/huanbao/index.html赛贝奇科学教育网：/上海康宁科技实验小学：/中国科协青少年部科学教育网：/少儿科学探索隧道：/kexuetansuosuidao/kexuetansuosuidao.htm科学时报科学网：/启三物理太空：/index.htm绿色学校网：/greenschools/index.htm中美合作网上科技教育资源：/usnew/新华网科技频道：/st/国家地理杂志（台湾）：/南京大学地球科学数字博物馆：http://202.119.49.29/museum/default.htm江苏省青少年科技教育协会：http://202.195.33.36/sciedu/default.asp节约用水：/savewater/科普世界官方网站：/新浪网科技搜索引擎：/search_dir/kx/国家海洋局/海洋科普：/kepu/index.html科普频道：/义庄科技园：/kejiyuan/武汉电视台科技之光：/main.htm教育科学出版社科学教育：/sc_art/science/index.asp国家地理杂志（美国）：/北京天文馆：/twg3/ze.htm中央电视台科技频道：/science/北京昆虫网：/index1.htm国家环境保护总局：/国家气象(气候)中心：/地球频道：/汉博.中国少儿科学教育网：/环保人之家：/index.htm中国活动教育网：/发明提示：/地球您好：/地震科普之窗：/北京大学科学传播中心：/北京百科全书网：/index.asp中国恐龙网：/天气e频道：/channele/index.html国家百科全书网：/index.asp《大自然探索》：/《科学世界》：/《小哥白尼》：/index.html《动手做》：/jinhulu/read/read.htm科学与您：/index_sc.htm科普类：中国科普博览：/gb/lives/animal/basic/index.html科普之窗：中国公众科技网：/科普城：科学在线：中华网中国科技：中国科普：飞碟探索杂志：.tw科技星空：/science科科网：生命在线：天津科学技术馆：航空航天博览：网上科学馆：天津科技网：赏鸟：/land/bird.htm中国海洋信息网：中国科学院北京天文台：http://159.226.88.50/bao星空热线：/~jxpsky大众天文园地：/pics云南省地质博物馆：/zrbw/dzbw深圳市科学馆：/bbs/kpy/index.htm航空航天博览：/museums/av.ation地球科学教室：http://140.115.123.30/earth.htm福建省科技馆：昆虫世界：/home/yanyu新加坡科学馆：.sg/ssc/ssc-c.html北京自然博物馆：/天津科学技术馆：中华奇幻：太阳系----the Nine Planets中文版： 上海自然博物馆：/kjww/szww中国科学技术馆：台湾自然科学博物馆：.tw/chi_version.html 中国给水技术博物馆：/台湾海洋生物博物馆：.tw/石尚矿物化石典藏馆：中国绿色时报：/上海科技城：/奇美博物馆：/museum/index.html岳阳市科技馆：/清蔚园科学馆：.tw/~vm/science/台湾野生动植物网：.tw旧金山探索博物馆：/天津自然博物馆：/脉搏网--自然与人频道：/hubdoors/0011/0011.asp 中国环境保护：/美国航空太空博物馆：上海环境网：/拯救地球：/摩天大楼博物馆：/绿色家园：/中国环境科学：/periodical/zghjkx/index.htm 环境保护新闻纵览：/info/np山东环境报：/gov/environprot/envpaper.htm广东环境保护：/山东环保热线：/gov/environprot/东方环境：/中国国家环保总局环境工程评估中心：/广东环境保护：/上海环境热线：/中国环境在线：/ceec/pvw10.htm新疆环境保护：/huanbao/xjepb.htm解放军在线：/军事图片网（快速版）：/~militarysoyou军事网：/war新龙环球军事：/环保法律、法规、标准：/law中国工程技术兵器信息网：/捷德在线棗军事快讯：/army/news.asp军事纵横：/ddg54舰船知识：/content.asp中国军事网：/《兵器知识》杂志：/视野边缘：/国防科技快讯：/世界军事之林：/文学城之军事广角：/。
十篇科学美国人文摘中英对照
注：英语原文来自SCIENTIFIC AMERICAN《科学美国人》第一篇：回归自然：聆听昆虫爱乐乐团交响曲 (1)第二篇：阑尾并非可有可无 (3)第三篇：今朝寻醉，明日“买单” (5)第四篇：大脑中掌管求“变”的部位 (6)第五篇：世界上最疯狂的地球工程方案 (8)第六篇：笔迹测谎 (10)第七篇：挑战交织在一起：气候变暖和能源使用 (11)第八篇：网瘾是病吗？ (13)第九篇：释放心灵，忘记不快 (15)第十篇：破解香槟之谜：关键是泡沫 (17)第一篇：回归自然：聆听昆虫爱乐乐团交响曲Allison Beall of the Marshlands Conservancy in Rye, N.Y., led a twilight walk on September 5th to tune in to the insect sounds of the evening. Become more aware of the nocturnal symphony and, in the New York metropolitan area, help scientists count the insects during the "Cricket Crawl" on September 11th.Allison Beall在纽约拉伊（Rye）的湿地保护区（Marshlands Conservancy）工作，她在9月5日的傍晚带领我们散步，去聆听夜间昆虫的声音。
在庆祝9月11日的“蟋蟀爬行日”时候，请进一步意识到我们周围的夜间交响乐，同时在纽约市区帮助科学家们统计这些昆虫。
回归自然：聆听昆虫爱乐乐团交响曲Tuning In to the Insect Philharmonic“Can you hear the end of the daytime insect? That’s the cicada. But I’m hearing crickets in the background, too. And just listen for a second, listen to how many different sounds you can hear.” That’s Allison Beall of the Marshlands Conservancy, a wildlife sanctuary in Rye, New York. She led a twilight walk through the preserve on September 5th.“There’s a wonderful event that’s about to take place, on September 11th. There’s going to be a 'Cricket Crawl,' where people are going to go out and listen for the sounds of seven crickets and katydids, angle-winged katydids, and coneheads and various other night insects that are singing. And you can go to a Web site, and you can go out into your own backyard and listen for the sounds and actually be part of this scientific count. So all of the sounds are on the Internet, you can listen, you can see the insect close-up, and you can hear the sounds, and then you can send in the data from your own backyard.”The Web site is /cricket or just google “Cricket Crawl.” The official count is taking place in the New York City metropolitan area, but anyone canget a new appreciation for the tiny wildlife producing nature’s nocturne.“Okay, so we are just about at the end of this walk, and I want to tell you something. It has not anything to do with this walk, this is called a crepuscular walk. It was just a trick, it was a trick to get you to go outside in your own habitat and to listen for the same things that have been in your backyard or in your neighborhood all along and you just haven’t paid any attention to them. So here’s what I recommend. You go out and you get a flashlight, and at eight o’clock go out and follow the sounds that you’ve heard here tonight. Do you realize how many different species of crickets and katydids and grasshoppers there are? And your job is to find them.”聆听昆虫爱乐乐团交响曲“你能听到白天昆虫停止鸣叫吗？那是蝉。
西南财大学术期刊等级分类目录
西南财经大学学术期刊等级分类
进行分级认定。 2．期刊分级。以 JCR 为依据，将英文期刊目录分为 A 级、B 级
（含学科 B 级）和 C 级。 （1）A 级期刊。A 级为国际公认顶级学术期刊，其影响因子排名
为所属学科前 8%的期刊。 （2）B 级期刊。B 级为国际知名学术期刊，其影响因子排名为所
学术期刊等级分类目录
（2013 年版）
西南财经大学科研处 编印 二〇一三年五月
西南财经大学学术期刊等级分类
根据《西南财经大学教师教学科研社会服务成果认定标准及奖励 办法》（西财大办[2013]3 号）中关于期刊分类与分级标准的相关规定， 编制《西南财经大学学术期刊等级分类目录（2013 版）》。
西南财经大学科研处 2013 年 5 月
3．同时被不同学科收录的少数期刊，按照影响因子排名的就高 原则进行认定。
三、中、英文期刊等级调整原则 在每类每级期刊数量保持不变的前提下，可进行适当调整。按照 有上有下的原则进行等量置换。英文类期刊置换原则上须满足上调的 期刊影响力大于下调的期刊的影响力，CSSCI 期刊须就上调期刊的影 响力给出充分理由，CSCD 期刊原则上须满足上调期刊的 H 指数大于 下调期刊的 H 指数。
1
西南财经大学学术期刊等级分类
期刊分类与分级标准
一、中文期刊分类与分级 1．基本依据。人文社会科学类期刊以南京大学社会科学评价中 心发布的中文社会科学索引（2012-2013 版,简称 CSSCI）为基本依据, 自然科学类期刊以中国科学院文献情报中心与中国学术期刊电子杂 志社联合开发的中国科学引文数据库（2011-2012 版,简称 CSCD）为 基本依据。 2．中文期刊分级 （1）A 级期刊。所属学科排名前 10%的期刊。如果某学科期刊少 于 10 本，则排名第一的为 A 级期刊。 （2）B1 级期刊。所属学科排名前 50%但未进入前 10%的期刊。 （3）B2 级期刊。未进入 A 级和 B1 级的 CSSCI 和 CSCD 学术期 刊以及北京大学图书馆《中文核心期刊要目总览》的学术期刊。 3．中文 B1 级及以上期刊的英文版作为同级别中文期刊予以认 定。被《新华文摘》全文转载的学术论文，视同 A 级学术论文予以 认定。 4．综合性社科期刊分类中除《中国社会科学》作为 A 级期刊外， 只遴选保留 5 本学术性较强的期刊作为 B1 级期刊，其余期刊均作为 B2 级期刊。 5．民族学与文化学类期刊中，保留《民族研究》作为 A 级期刊， 不设置 B1 级期刊，其余均为 B2 级。 6．遵从我校期刊目录惯例，高校综合性学报不设 A 级期刊，只 设 10 本 B1 级期刊。 二、英文期刊分类与分级 1．基本依据。采用 Thomson-ISI 发布的国际公认的《期刊引证 分析报告（JCR）》（含自然科学版 SCI 和社会科学版 SSCI），按照其 学科分类体系，主要根据收录期刊影响因子大小（非唯一考量因素）
科学美国人10年8月
Mars Rover Spirit Is Dead Silent--but May Not Be DeadAugust 2, 2010 As many of us broil in August heat, the Mars rover Spirit is hunkered down to survive a far more brutal season—a Martian winter. Spirit’s been on Mars since January 2004 and already survived previous winters, which run from May through November. With sunlight reaching Spirit at a weak angle, the rover hibernates and uses the scant solar power to recharge batteries and heat itself to –40 degrees [Fahrenheit].At least, that’s what’s happened in previous winters. This winter, the game little unit just doesn’t have enough juice to keep its heaters on, so temperatures inside the rover will plunge to a frigid –67 degrees Fahrenheit.When NASA scientists began signaling Spirit on July 26, they hoped to receive a communications beep back—but so far there’s only silence.The researchers say that in about two months sunlight will start to increase again through March 2011. If we haven’t heard from Spirit by that point, then the likelihood is that we never will. The rover was designed to work on Mars for three months, but was mobile for more than five years. Now mission scientists wait through the Martian winter to see if this ET will phone home.—Cynthia GraberPhysics Students Reveal Bias for Male LecturersAugust 3, 2010 Why aren’t there more women physicists, and in senior positions? One factor may be unconscious biases that could keep women physicists from advancing—and may even prevent women from going into physics in the first place.Amy Bug, a physicist at Swarthmore College, examined the bias question.* Her research team trained four actors—two men, two women—to give a 10-minute physics lecture. Real physics classes watched the lecturers. Then the 126 students were surveyed.When it came to questions of physics ability—whether the lecturer had a good grasp of the material, and knew how to use the equipment—male lecturers got higher ratings by both male and female students.But when asked how well the lecturer relates to the students, each gender preferred their own. And while female students gave a slight preference to female lecturers, male students overwhelmingly rated the male lecturers as being superior. The research appears in the journal Physics World. [http://bit.ly/b3ctOj]Bug says the results may be evidence of inherent biases that could hold women back—along with economic inequalities, such as lower wages and smaller start-up grants. Which reduce career acceleration and thus the amount of force available to crack the glass ceiling.—Cynthia Graber*Correction (8/3/10): This sentence has been edited to correct an error conveyed by this podcast. Swarthmore College was originally identified as Swarthmore University.Hot Peppers' Capsaicin Helps Hypertensive RatsAugust 4, 2010 Here’s a possible blood pressure remedy. But it’s only for those who can stand the heat. It’s capsaicin, the “active ingredient” in peppers like habaneros that should probably be sold by prescription only. While lips burn and eyes water, blood vessels actually relax, thanks to increased production of the signaling molecule nitric oxide. In rodents, anyway.For seven months, researchers in China fed a steady diet of capsaicin to rats bred to be hypertensive. Long-term consumption of the chemical substantially lowered the rats’ blood pressure. The results appear in the August issue of the journal Cell Metabolism. [Dachun Yang et al., http://bit.ly/aLcuZZ]Previous research found mixed results with capsaicin, but those studies only looked at short-term effects. Human trials are needed, but there’s already a clue. Some 20 percent of people in northeastern China have high blood pressure. But the southwest—where hot peppers are a dietary staple—has a much lower incidence, half in some places.Human studies could also confirm whether the habanero, as legend has it, can cause hearing loss. Allegedly so that diners don’t have to listen to their own screams.—Adam Hinterthuer[The above text is an exact transcript of this podcast.]Audio Finds Frog Counters May Be OverestimatingAugust 5, 2010 Declining frog populations are considered an indicator of environmental damage. But new research finds that frogs might be doing even worse than we thought. Because the volunteers who count frogs by their sounds may be overestimating.The North American Amphibian Monitoring Program is the country’s largest frog-counting system. Volunteers listen for frogs, identify the species, and give population estimates. They’ve been doing this for over a decade.Ted Simons from North Carolina State University and colleagues put recordings of frogs, like this wood frog, [Wood Frog sound] in the field to test the volunteers. They call it Ribbit Radio.Many volunteers ended up with false positives—they named frog species whose calls weren’t being played. So there may be fewer frogs, or less variety, than the surveys suggest. The results appear in the journal Ecology. [Brett McClintock et al., http://bit.ly/9iPhUs]Simons is working with the U.S. Geological Survey—in charge of the amphibian monitoring—to account for these false positives, and to better train the volunteers—so they don’t write down “chorus frog” [Chorus Frog sound] when all there really was were pickerel frogs. [Pickerel Frog sound] Apparently, it’s not easy being green, for humans either.—Cynthia Graber[The above text is an exact transcript of this podcast.]Transgenic Canola Plants Break Free of FarmAugust 6, 2010 One of the concerns about working with genetically modified crops has been that vegetation growing in agricultural fields might escape out into the world. Now, for the first time in the U.S., researchers report a large population of GM crops beyond the farm.Transgenic canola plants in North Dakota had received genes making them resistant to herbicides, such as the weed killer Roundup. Researchers collected and tested 406 canola plants along thousands of miles of state roads. They found 347 carrying at least one resistance gene. There were also indications that the inserted genes were being passed on to new generations, producing some plants in the wild with multiple transgenes. The findings were presented on August 6th at the annual meeting of the Ecological Society of America in Pittsburgh. [Meredith Schafer et al., University of Arkansas]The transgenic canola plants are not about to take over the world. But researchers are obviously curious about how these particular plants managed to make it in places like the edges of parking lots rather than pampered fields. Any answers they find will likely affect future biotechnology regulation.—Molly Webster[The above text is an exact transcript of this podcast]Blue Whales Synchronize Song PitchAugust 9, 2010 Blue whales off the California coast make calls that, sped up 10 times, sound like (sound of two-part call). The original is a wall-rattling frequency too low for us to hear. Scientists analyzed around 2,500 of those calls, and found that the second part (sound) is nearly identical in pitch every time from each whale: 16 hertz, or four octaves below middle C. And the slight variations in frequency that do exist are only a tenth of the difference between a C and a C sharp. Those findings appear online in the Journal of the Acoustical Society of America. [Michael Hoffman, Newell Garfield and Roger Bland, http://bit.ly/9oCoP0]The researchers don't know how many different individual whales they caught singing, or why even they sing at all. But past studies suggest only blue whale males make calls like this. So the investigators speculate that males might synchronize to a single common pitch as a sort of mating beacon.Thanks to the Doppler effect, females swimming towards a male would hear a slightly higher pitch; swimming away, a lower-pitched moan. Serenade out of tune—you might be swimming solo tonight.--Christopher Intagliata[The above text is an exact transcript of this podcast.]Case Study: Tongue Stud Play Causes Front Teeth GapAugust 10, 2010 That’s what it might sound like if I had a tongue stud, hitting my teeth. Maybe you’ve seen people with studs in their tongue clicking it up against their front teeth, a move known as “playing.” But it turns out that the habit may destroy some smiles.University of Buffalo researchers noticed that local high school students who had a barbell-type tongue stud commonly pushed the piercings against their front teeth. Then they examined a 26-year-old patient at the school’s dental clinic. She’d had been complaining about a large gap that had developed between her front two teeth. Seven years previously, she got a tongue stud. And every day, for seven years, she pushed that stud up against her teeth.The researchers say tongues are strong, and it makes sense that the force of “playing” will move teeth, even forcing them apart. The case was written up in the Journal of Clinical Orthodontics. [Sawsan Tabbaa, Ivanka Guigova and C. Brian Preston, ]Tongue piercings have also been associated with infections, chipped or broken teeth, and gum trauma. And the patient? She got braces to push her teeth back together. Which probably didn’t look quite as cool as she thought the tongue stud was.—Cynthia Graber[The above text is an exact transcript of this podcast.]Almost a Million Years Added for Earliest HumanAncestor Stone Tool Use and Meat-EatingAugust 11, 2010 There’s nothing like a good steak. And our Australopithecus afarensis ancestors apparently felt the same way. Because new discoveries from Ethiopia show that what was likely the species of the famous fossil Lucy used stone tools to butcher meat from big mammals—about 3.4 million years ago. That’s a million years earlier than our best previous evidence for human ancestor stone tool use and meat eating. The finding appears on the cover of the journal Nature. [Shannon P. McPherron et al., http://bit.ly/dzCs4d]The research team found two fossil bones with cut and scrape marks, signs of meat carving. One bone was a piece of rib from a cow-sized mammal; the other, a leg bone fragment from a mammal the size of a goat. The bones also had percussion marks, sustained while Lucy’s friends smashed the bones to get at the marrow.It looks like the ancient tool users collected stones that happened to have shapes conducive to butchering, the way kids select particular stones with good potential to skip on water. But future expeditions will look for evidence for any attempts at shaping stones into kitchen utensils. Because after 3.4 million years, Lucy and her fellow afarensis keep surprising us.—Steve Mirsky[The above text is an exact transcript of this podcast.]Sound Sleepers' Brain Waves Block SoundsAugust 12, 2010 Ahhh, sleep. There’s nothing better than a nice, long, uninterrupted [LOUD NOISE]. Awwgh. I can’t sleep when there’s [NOISE]. But d’ya ever notice: noise [NOISE] doesn’t wake everyone. Now scientists have a better idea why. Because sound sleepers show a certain brain rhythm when they doze, findings published in the journal Current Biology. [Thien Thanh Dang-Vu et al., http://bit.ly/cORe7D]To study the brain waves of a good night’s sleep, scientists invited volunteers to snooze in the lab. While the subjects caught some Zs, the researchers monitored their brain activity. They then subjected the sleepers to [NOISE] or [NOISE]. And they found that those who were able to slumber straight through all the [NOISE] showed more short bursts of faster brain waves. This activity, the scientists say, is the brain’s way of blocking out the [NOISE] and the [NOISE] while you’re trying to rest.The scientists don’t yet know of any way to boost those sleep-saving brain waves. So until then, shut the door [DOOR SHUTTING], make sure the late show’s on a timer [TV SOUND], and try to have sweet dreams.—Karen Hopkin[The above text is an exact transcript of this podcast.]Pour Champagne on the Side for Better FlavorAugust 13, 2010 You don't have to be a champagne buff to want the best flavor from your bubbly. So the secret to a perfect glass? It's all in the pour, according to a study in the Journal of Agricultural and Food Chemistry. [Gerard Liger-Belair et al., http://bit.ly/cmmEOH]A key player in champagne's taste is its dissolved carbon dioxide. As that CO2 bubbles out, it releases aroma, and provides that tingly bite. As soon as you uncork a bottle, CO2 starts diffusing from the champagne into the air. But pouring it speeds up that process, by increasing surface area and turbulence.Chemists—French ones, of course—poured champagne into fluted glasses two ways. The traditional way, straight down, splashing off the bottom—and the beer way, onto the side of a tilted glass. Then they measured the CO2 lost during the pour.At 40 degrees Fahrenheit, champagne poured traditionally quickly lost a quarter of its carbon dioxide. But pouring down the side caused only half the gas loss. Closer to room temperature, the drink became flat fast, whatever way you pour. So if you want your champagne très bon, keep it cold. And pour that bubbly like it’s Bud.—Christopher Intagliata[The above text is an exact transcript of this podcast.]Invasive Species Lets Other Species Disrupt EnvironmentAugust 16, 2010 At Point Reyes National Seashore in Marin County, California, a plant called Tidestrom’s lupine is holding on for dear life. Its survival has been threatened by the appearance of another plant, an invasive species called European beachgrass. So, does the beachgrass simply outcompete the lupines for land and light? Not at all, according to researchers at Washington University in St. Louis.Tiny deer mice have a taste for the seeds of the lupines. These critters would ordinarily think twice about approaching the plants. Because exposed out on the sand, they’re easy pickings for birds interested in a rodent repast. But the beachgrass provides excellent cover. The mice use the grass to get close enough to pilfer seeds before any hungry birds pilfer the mice. The research appears in the August issue of the journal Ecology. [Emily Dangremond, Eleanor Pardini and Tiffany Knight, http://bit.ly/9yaeIK]The information may be useful for a proposed dune restoration project. And the unexpected consequences of the invading species bring to mind this well-known comment by ecologist Aldo Leopold: “To keep every cog and wheel is the first precaution of intelligent tinkering.”—Steve Mirsky[The above text is an exact transcript of this podcast.]Public Underestimates Savings of Energy EfficiencyAugust 17, 2010 Most of us know we should rein in our energy use. But to be successful, it’d help if we knew the best way to do it. So scientists asked more than 500 people, “What’s the most effective thing you can do to conserve energy?” The results were illuminating.More than half the participants focused on conservation by curtailment: switching off the lights, changing thermostat settings and driving less. Only 12 percent went for efficiency: using compact fluorescent bulbs, insulating the house or driving a hybrid car. But scientists say that it’s actually these moves that yield the bigger energy savings. The results appear in the Proceedings of the National Academy of Sciences. [Shahzeen Attari et al., http://bit.ly/bEtA6W]The study authors think that a big factor is that curtailment is easier to imagine doing—while efforts to improve efficiency would involve, for example, doing research about new appliances or cars, and spending money up front to buy them.But if people knew more about the actual energy requirements of their activities versus the savings available through efficiency, they might be spurred to act. To quote physicist and energy expert Arthur Rosenfeld: “Energy efficiency is like a Saudi Arabia under our cities.”—Karen Hopkin[The above text is an exact transcript of this podcast.]Atlas Identifies Regions of Worm InfectionsAugust 18, 2010 Shakespeare noted that a worm may eat a king, after that king is dead. Sadly, parasitic worms infect people who are still alive, especially kids. Public health advocates estimate that a third of the people on earth are infected with parasitic worms, called helminthes, particularly in poorer areas with inadequate sanitation.Helminths harm health, but also interfere with nutrition and even academic advancement. So the London School of Hygiene and Tropical Medicine, with the Partnership for Child Development at Imperial College London, launched what’s called This Wormy World. It’s an atlas of the distribution and prevalence of helminth diseases, including roundworm, hookworm and whipworm. []It’s often easy to control the parasites with cheap treatments. But resources get wasted because deworming programs are targeted at the wrong communities. The atlas should help the eradication fight by letting health officials know just where the problem areas are.The scientists have been collecting data for the past decade. Their first map focuses on Africa, where worm infestations are worst. Maps for the rest of the worldwill be out by the end of 2010—providing a complete picture of this wormy world of ours. And a new tool to tackle it.—Cynthia Graber[The above text is an exact transcript of this podcast.]Trusting Souls Excel At Spotting LiarsAugust 19, 2010 When you think of someone who’s trusting, you may assume that they’re gullible. But that’s not necessarily true—a fact that your Pollyanna pal might be in a good position to point out. Because people who have faith in their fellow human beings are actually good at spotting lies. The finding is described in the journal Social Psychological & Personality Science. [Nancy Carter and J. Mark Weber, http://bit.ly/bOEFLN]Researchers videotaped a cadre of second-year MBA students as they pretended to interview for a job. Half the interviewees were entirely truthful, and half told at least three whoppers, lies they thought would make them more attractive candidates for the fake job.The scientists then showed these videos to a second set of subjects and asked them to rate the honesty of the interviewees and say which ones they’d hire. The results: subjects who said they think that most people are basically honest, good-natured, and kind were better at spotting the liars than the self-described cynics. Subjects who were more suspicious were, ironically, more likely to hire the liars and less likely to detect their fabrications.So trust may lend itself to better interpersonal intuition. And if you don’t believe that, well, maybe you’re just not being honest with yourself.—Karen Hopkin[The above text is an exact transcript of this podcast]Low-Level Moral Transgressions Make Us LaughAugust 20, 2010 Everyone from Freud to Tina Fey has tried to understand why some things are funny. Now, new research concludes that one key to comedy is for a situation to violate a moral standard, but in a gentle way.Researchers presented volunteers with a number of different scenarios. For example, the Jimmy Dean sausage company needs a spokesman for its new line of pork products, so they hire Rabbi Shlomo Rosenfield. Or, so they hire a farmer. Participants were more likely to find the rabbi scenario wrong, but they were also more likely to think it was funny.The researchers found that participants would laugh at situations with moral violations if, for example, they felt that situation was hypothetical, harmless or involved people unconnected to the listener. The study appears in the journal Psychological Science. [A. Peter McGraw and Caleb Warren, http://bit.ly/c48IZJ]The finding deviates from previously published psychology studies which equate moral violation solely with disgust. It also proves that Mel Brooks was onto something when he said, “Tragedy is when I cut my finger. Comedy is when you fall down an open sewer and die.”—Molly Webster[The above text is an exact transcript of this podcast]Solar Panels Dust Themselves OffAugust 23, 2010 Imagine giant fields filled with photovoltaic solar panels, soaking up rays. The best spots to put such panels are obviously sunny, with little rain. But such places often come with lots of dust. And the panels have to stay dust-free: just a seventh of an ounce of dust per square yard of panel can decrease solar power conversion by 40 percent. And panels in Arizona might get covered with four times that much dust each month.Cleaning the panels conventionally uses precious water. So researchers are turning to dust-cleaning technology developed for one of the driest, dustiest locations possible: Mars. The work was reported at the national meeting of the American Chemical Society. [Malay Mazumder et al]An electrically-sensitive transparent material is deposited on glass or a plastic sheet that covers the panel. Sensors monitor the dust levels. Once the dust reaches a specified level, the system reacts and produces a charge, with electricity generated by the panel.The charge creates a wave over the material’s surface that physically lifts the dust and tosses it over the edges. The system gets about 90 percent of the dust in a couple of minutes. So the panels can go back to soaking up rays.—Cynthia Graber[The above text is an exact transcript of this podcast]。
美《科学》杂志揭晓今年十大科学进展发现“上帝粒子”居首
美《科学》杂志揭晓今年十大科学进展发现“上帝粒子”居首美国《科学》杂志网站20日公布了该刊评选的2012年十大科学进展，其中发现被称为“上帝粒子”的希格斯玻色子被列为本年度最大科学突破。
希格斯玻色子是英国教授彼得·希格斯在上世纪60年代的理论研究中预言存在的粒子，是物质的质量之源，其他粒子在希格斯玻色子构成的“海洋”中“游弋”，受其作用而产生惯性，最终才有了质量。
在物理学“标准模型”所预言的基本粒子中，希格斯玻色子是最后一种被证明存在的基本粒子，由于它极为重要又难以寻觅，曾有人开玩笑说它是“上帝诅咒的粒子”，后来常被称作“上帝粒子”。
欧洲核子研究中心今年7月4日宣布，该中心的两个强子对撞实验项目——atlas和cms均发现一种新的粒子，具有和科学家们多年以来一直寻找的希格斯玻色子相一致的特性。
数据的确定性为5西格玛，即理论物理界可以确认“发现”的水平。
《科学》杂志认为，这项发现将“标准模型”拼图中的最后一块填充到位，虽然尚不清楚该发现未来将把粒子物理领域引向何处，但其对物理学界的重大影响不可否认。
《科学》杂志总编辑布鲁斯·艾伯茨在社论中表示，希格斯玻色子的发现“既是人类智慧的胜利，也是全球数千名物理学家和工程师数十年辛勤工作的顶峰”。
其他九项进展包括：丹尼索瓦人基因组：德国马克斯·普朗克进化人类学研究所科学家开发出一种将特定分子与单股dna相结合的新技术。
通过这种技术，他们利用一个距今7.4万年至8.2万年的指骨碎片获得了丹尼索瓦人的基因组高覆盖率测序数据，重建其基因组全序列。
从如此古老的样本中制作出高品质全基因组，意味着科学界在古代dna测序领域取得巨大进步。
用干细胞制造卵子：日本京都大学研究小组今年10月报告说，他们首次利用诱导多功能干细胞成功培育出实验鼠的卵子，并使其受精从而诞出健康小鼠。
实验结果未能达到科学家们的终极目标——完全在实验室中得到卵细胞，但它为研究基因及其他影响生育和卵细胞发育的因素提供了强有力工具。
科学文献
M a c h in ev is io nf o rc o n t r o l l in gm o v in g3D r e‡e c t iv ep r o d u c t sG.D e l c r o ix¤y,D.A l u z e y,F.M e r ie n n e y,H.Je n d e r z,a n dC.D u mo n t y;¦.y L a b o r a t o ir eL e2i,IU T,12R u ed el aF o n d e r ie,1200L eCr e u s o t,F r a n c e.z E c o l eSu p.d eTe c h n o l o g ieO u j d a,U n iv e r s itéM o h a mme d1,B P43,60000O u j d a,M a r o c.¦IR IS L a b o r a t o r y,U n iv e r s it yo fT e n n e s s e e,325F e r r is H a l l,Kn o x v il l e,T N3996.A B ST R A C TF o rma n yy e a r s,ma n u f a c t u r e r sh a v eb e e nb o t hma n a g in ga n da s s u r in gt h eq u a l it yo ft h e irp r o d u c t s.A mo n g t h e ma n y c o n c e p t s u s e d a tpr e s e n t,a r t i…c ia lv is io n is c h o s e n t o c o n t r o lc o n f o r mit y d u r in g t h e p r o d u c t io n p r o c e s s.T h e r e a lt ime c o n t r o lo f3D r e‡e c t iv e o bj e c t s is o u rc o n c e r n in t h is r e s e a r c h w o r k.In t h e r e c e n t p a s t,w o r k h a s b e e n d o n e s h o w in gt h e c a p a b il it y o fa v is io n s y s t e m f o rd e t e c t in ga n d me a s u r in gd e f e c t s o n n o n-mo v in g3D r e‡e c t iv ema n u f a c t u r e dp r o d u c t s.F o rt h is n e win d u s t r ia la p p l ic a t io n,d e f e c t s w ea r et r y in gt o d e t e c ta r ed u s t s in c l u d e d u n d e rt h e me t a l l icl a y e ro fp r o d u c t s.T h ed e f e c td e t e c t io n is s t il lb a s e d o n t h eu s e o fa s pe c i…cl ig h t in gs y s t e m c o mpo s e d o fl ig h ts t r ipe s.B y e x a min in gt h e r e‡e c t io n o fl ig h tf r o m o bj e c t,w e a r ea b l et od e t e c td e f e c t s b e t w e e nt w oc o n s e c u t iv ew h it es t r ipe s.T h eo p t ima ld e t e c t io n h a s b e e no b t a in e db ya d j u s t in gt h ec h a r a c t e r is t ic so ft h el ig h t in gs y s t e m w h il et a k in gin t oa c c o u n tt h e3D g e o me t r yo ft h ed e f e c t st ob ed e t ec t e d.T h ema c h in ev is io ns y s t e m pe r f o r ms t h ec o n t r o lo fo n ec y l ind r ic a lp r o d u c tw it h in o n ese c o n d.Ke y w o r d s:Q u a l it y Co n t r o lb ya r t i…c ia lv is io n,L ig h t in gs y s t e m,R e‡e c t iv eSu r f a c e s,R e a lT imec o n t r o l, M o v in gP r o d u c t s.1IN T R O D U C T IO NN o w a d a y s,ma n u f a c t u r e r s a t t a c hg r e a timpo r t a n c et ot h eq u a l it yo ft h e irma n u f a c t u r e dp r o d u c t s.Q u a l it y c o n t r o lo c c u r sd u r in gt h ep r o d u c t io nt h r o u g hd i¤e r e n tw a y s s u c ha s f u n c t io n a lc o n t r o l,p r o c e s sc o n t r o l,a sw e l l a s a s pe c to rd ime n s io n a lc o n t r o l.In o r d e rt or e a l iz et h e s e c o n t r o l s,a r t i…c ia lv is io n is t o d a y av e r y c o mmo n, u s e f u l lt o o l.T h e q u a l it y c o n t r o la p p l ic a t io n w e a r e p r e s e n t in gin t h is p a pe rc o n c e r n s t h e d e f e c td e t e c t io n o n me t a l l ic o bj e c t s.Sin c et h el a s tf e wy e a r s,q u a l it y c o n t r o la p p l ic a t io n s h a v e b e e n pe r f o r me d o n e it h e rp l a n e r e‡e c t iv e s u r f a c e s[1]o rr o u g h3D me t a l l ics u r f a c e s[2][3].Int h er e c e n tpa s t,r e s e a r c h w o r k[4][5]h a s b e e n d o n es h o w in g t h e c a p a b il it y o fav is io n s y s t e m f o rd e t e c t in ga n d me a s u r in gd e f e c t s o n n o n-mo v in gr e‡e c t iv ema n u f a c t u r e d p r o d u c t s.T h ev is io ns y s t e m s h o w nin[6]is a b l et oc o n t r o ld u s t s in c l u d e du n d e rt h eme t a l l icl a y e ro fp r o d u c t s b y u s in gao r ig in a ll ig h t in gs y s t e m.T h ed e f e c td e t e c t io n me t h o d c o n s is t s in e x a min in g[7][8][9]t h er e‡e c t io n o ft h el ig h t in gs y s t e m o n o bj e c ts u r f a c e.O u rc o n c e r n,f o rt h is p r e s e n t e d in d u s t r ia la p p l ic a t io n,is s t il lt h e c o n t r o lo fh ig h l y r e‡e c t iv e o bj e c t s.T h e u s e d d e f e c td e t e c t io n me t h o d is a l s ob a s e do n t h e u s eo ft h is s pe c i…cl ig h t in gs y s t e m.T h eo r ig in a l it y o ft h is ¤F u r t h e ra u t h o rin f o r ma t io n-Sc h o l a r s h ip o ft h e B u r g u n d y R e g io n a lCo u n c il.n e wr e s e a r c h w o r k c o n c e r n s t h e o n -l in e c o n t r o lo f3D h ig h l y r e ‡e c t iv e ma n u f a c t u r e d p r o d u c t s f o rw h ic h t h e ma in c o n s t r a in tt od e a lw it h is t h eh ig h p r o d u c t io n r a t et h a tis a b o u to n ep r o d u c tw it h in as e c o n d.F ig u r e1:T h ep r o d u c tt oc o n t r o lv ie wu n d e ra m b ia n tl ig h t in gF ir s t ,w e a r e b r ie ‡y p r e s e n t in gt h e u s e d l ig h t in gs y s t e m a n d t h e n it s mo d e l iz a t io n in o r d e rt o d e …n e it s c h a r a c t e r is t ic s a l l o w in gin t h a tw a yt h eo p t ima ld e t e c t io n o ft h ed e f e c t s .F a s tima g ep r o c e s s in ga r et h e n p r e -s e n t e da l l o w in gt h ec o mp l e t e ,f a s td e f e c td e t e c t io n .T h ed e c is io n a b o u te it h e ra c c e p t in go rr e j e c t in gp r o d u c t s isma d ea c c o r d in gc r it e r ias u c ha sn u mb e ro fd e t e c t e dd e f e c t sa n dn u m b e ro fp ix e l sf o re a c hd e f e c t .T h isa r t ic l e is e n d e db yt h ep r e s e n t a t io no fc o mpl e t ein d u s t r ia ls y s t e m p r o t o t y pe .2D E SC R IP T IO N O F T H E L IG H T IN G SY ST E M F O RD E T E C T IN G D E F E C T S O N R E F L E C T IV E SU R F A C E SD e s p it e t h e u s e d l ig h t in gs y s t e m h a s b e e n a l r e a d y p r e s e n t e d in [4][6],w e a r e b r ie ‡y d e s c r ib in gitin t h is s e c t io n .It s p r in c ip l e c o n s is t s in o b s e r v in gt h e r e ‡e c t io n o fa s pe c i…c l ig h t in g o n t h e o bj e c ts u r f a c e t h a tis c o mp a r a b l et oamir r o r .T h el ig h t in gis c o mpo s e do fl ig h tt r a n s it io n s a s itis s h o w nin…g u r e4a .Sin c ed e f e c t s a r el o c a t e du n d e rt h eme t a l l icl a y e rt h e yl o c a l l yc h a n g et h es u r f a c eo r ie n t a t io no fo bj e c t s .D e f e c t s r e ‡e c tl ig h t r a y s d i¤e r e n t l y a s s u r r o u n d in g‡a w l e s s s u r f a c e s (…g u r e 2b )a n d t h e y a p pe a rb y r e ‡e c t io n e it h e rw h it e o n a b l a c kb a c k g r o u n do rb l a c ko n aw h it eb a c k g r o u n da s w es e ein …g u r e3.Specular2(a)(b)F ig u r e 2:a )s h o w s t h e p r in c ip l e o ft h e u s e d l ig h t in gs y s t e m,a n d b )g iv e s t h e l u min o u s r a y s in t h e c a s e o f d e f e c tdF ig u r e3:D e f e c t s c a na p pe a rw h it eo n ab l a c kb a c k g r o u n do rb l a c ko n aw h it eo n eT h e q u a l it y o ft h e d e f e c td e t e c t io n d e pe n d s ma in l y u po n t h e d is t a n c e d r e f e r e n c e d a b o v e b e t w e e n t h e d e f e c t s a n d t h ebe g in n in go ft h et r a n s it io n o fl ig h t .T h ed is t a n c eis f u n c t io n o ft h eo bj e c ts h a pe ,t h el ig h t in g s y s t e m,a n d t h e o r ie n t a t io n s o fb o t h t h e c a me r a a n d t h e l ig h t in g s y s t e m w it h r e s pe c tt o t h e o bj e c tbe in g c o n t r o l l e d .T h ef o l l o w in gs e c t io np r o v id e s ama t h e ma t ic a ld e s c r ip t io no ft h eu s e dl ig h t in gs y s t e m a l l o w in gt h e d e t e r min a t io n o ft h eo p t ima ls e to ft h ev is io n s y s t e m p a r a me t e r s .2.1L ig h t in gs y s t e m m o d e l i n gW e p r e s e n tin …g u r e 4a 2D o pt ic a lmo d e lo ft h e v is io n s y s t e m in c l u d in g t h e CCD ma t r ix ,t h e p in h o l e mo d e lo ft h ec a me r a(fis it s f o c a ll e n g t h ),t h el ig h t in gs y s t e m a n dt h eo bj e c tt ob ec o n t r o l l e d .CCD MATRIXLIGHTING S(0,z s →j →k→i F ig u r e4:g e o me t r ic a lmo d e lo ft h ev is io n s y s t e m in c l u d in gt h ea x is o fb o t h c a me r aa n dt h el ig h t in gs y s t e m.F r o m t h is mo d e lw e c a n f o r mu l a t e t h e f o l l o w in g e q u a t io n s ,w h ic h g iv e t h e r e l a t io n be t w e e n t h e po in t s C (x c ;0)a n d S (0;z s )in f u n c t io n o ft h el o c a t io n o ft h epo in t P (x p ;z p )on t h eo bj e c ta n d it s o r ie n t a t io n g iv e n b yt h ea n g l e °.If °6=45±,z s =¡f ¡t a n2°x c +f ¢t a n2°¢(H p +x p )¡f ¢x p x c+f ¡L (1)e l s e z =(H +x p )¢x c ¡f ¢x p +f ¡L (2)W e p r e s e n tb e l o win …g u r e 5b ,as im u l a t io n o ft h e r e l a t io n b e t w e e n t h epo in t s C a n d S c o r r e s po n d in gt o t h eo bj e c ts h a pes h o w n in …g u r e5a .-20-15-10-505101520-20-15-10-55101520-3-2-10123-400-300-200-100100200300Xc [mm]Zs [mm](a)Xp [mm]Zp [mm](b)F ig u r e5:a )r e p r e s e n t s t h eo bj e c ts h a pea n db )is t h ec o r r e s po n d in gpo in t -t o -po in tr e l a t io nb e t w e e nt h eCCD ma t r ixa n dt h el ig h t in gs y s t e mIn t h e…g u r ea bo v e ,t h epo in to n t h eCCD c a me r aa tt h el o c a t io n x c =1mm co r r e s po n d s r o u g h l yt ot h e po in to n t h e l ig h t in ga tt h e l o c a t io n z s =0mm.Sinc edef e c t s c h a ng e th e l o c a lo r ie n t a t io n °o ft h e o bj e c t s u r f a c e ,t h iss pe c i…cl o c a t io nint h el ig h t in gma yb ed i¤e r e n tw h e t h e rt h el u min o u s r a y se n c o u n t e rad e f e c t .In t h ec a s eo fape r f e c t l y‡a to bj e c tw it has ma l ld e f e c tmo d e l e db yaG a u s s ia nf u n c t io n ,w eo b t a int h ef o l l o w in g g r a p h (F ig u r e 6)g iv in gt h e c o r r e s po n d e n c e b e t w e e n a po in tC o n t h e CCD c a me r a a n d a po in tS’o n t h e l ig h t in gs y s t e m.T h epo in tS is t h ev ie w e dpo in to n t h el ig h t in gs y s t e m ift h e r ew e r en od e f e c t .-0.1-0.0500.050.10.15C Xs [mm]Area corresponding F ig u r e6:po in t -t o -po in tr e l a t io n f o raG a u s s ia nd e f e c tl o c a t e do n ap l a n er e ‡e c t iv eo bj e c tT h is p r e v io u s g r a p h s h o w s a s ig n i…c a n td i¤e r e n c e b e t w e e n t h e l o c a t io n s o ft h e po in t s S a n d S’.U s in ga l ig h t in gs y s t e m c o mpo s e d o fo n e t r a n s it io n o fl ig h t(i.e .l ig h t e d v e r s u s n o n -l ig h t e d ),po in t s C o n t h e o bj e c t s u r f a c e c o r r e s po n d in gt od e f e c t s w il lr e ‡e c tl u min o u s r a y s s u c h a s t h e y r e a c h a l ig h t e d a r e a o n t h e l ig h t in g s y s t e m w h il e o t h e rpo in t s a r e a s s o c ia t e d w it h n o n -l ig h t e d a r e a s .W e s h o win …g u r e t h e l o c a t io n s o ft h e l ig h tt r a n s it io n w it h r e s pe c tt ot h e d e f e c tl o c a t io n .F ig u r e 8g iv e s t h e l u min a n c e in f o r ma t io n v ie w e d b y t h e CCD c a me r af o rt h et w od i¤e r e n tl ig h tt r a n s it io n l o c a t io n s (1a n d 2in …g u r e7).T h e r e f o r e ,d e pe n d in gu po n t h e l ig h tt r a n s it io n l o c a t io n t h e d e f e c t s ma y a p pe a re it h e rw h it e o n ab l a c kb a c k g r o u n d o rb l a c ko n aw h it e b a c k g r o u n da s ith a s b e e n s h o w n in …g u r e3.-0.1-0.0500.050.10.15Location of the lighttransition Xc [mm]F ig u r e7:L o c a t io n s o ft h el ig h tt r a n s it io n w it h r e s pe c tt ot h ed e f e c tl o c a t io nLuminanceLuminance Xc [mm]0.05-0.050(a)(b)F ig u r e8:L u min a n c ef u n c t io n c a p t u r e db yt h ec a me r ac o r r e s po n d in gt ot h el ig h tt r a n s it io nl o c a t io n s g iv e n in …g u r e7s o l u t io n s h o w n in …g u r e9o n l ya l l o w s t h ep a r t ia ld e t e c t io n o fd e f e c t s l imit e d b y t h eb o l d a r r o w s ma r k e do u t int h is s a me10.T h is l e a d s t oa nin c o mp l e t ed e f e c td e t e c t io na n dd e f e c t s w o u l da p pe a rs ma l l e rt h a nt h e ya r e :i.e .t h e ire d g e s w o u l db ec o n t r a c t e da n dt h e irc e n t e rw o u l db ev ie w e din b l a c ka s w ec a n s e ein …g u r e11.2.2P r o p o s i t io no fa no p t im a ls o l u t io nT h er e s u l t so ft h es im u l a t io ns h o wt h a tino r d e rt od e t e c ta tl e a s tf e wp ix e l sb e l o n g in gt oad e f e c t ,t h eb l a c k s t r ipen e e d st ob es ma l l e rt h a nt h ed is t a n c eD n o t ic e dint h ep r e v io u s…g u r e .T h isd is t a n c ema yb ed e t e r min e d b y k n o w in gt h e ma x ima ld e f e c ts iz ea n du s in gt h er e l a t io n s h o w n in …g u r e9.H o w e v e r ,t h es e n s ib il it yo ft h e d e t e c t io n v a r ie s in f u n c t io n o ft h ed is t a n c ed e f e c tt ol ig h tt r a n s it io n :t h el a r g e ris t h eb l a c ks t r ipe ,t h ew o r s e is t h ed e t e c t io n ,s ot h a tav e r ys ma l ld e f e c tma yn o tb ed e t e c t e d .T h eo b v io u s s o l u t io nc o n s is t s in s e t t in gt h e s t r ipe w id t h s ot h a tt h e s ma l l e s td e f e c tt obe d e t e c t e d w o u l d b e o p t ima l l y d e t e c t e d :i.e .t h e d e f e c ts u r f a c e t e n d s t oama x im u m a s w es h o win …g u r e11.T h e p r e v io u s pr o po s e d s o l u t io n u s in gt w ob l a c k s t r ipe s l e a d s t oin c o mp l e t e d e f e c td e t e c t io n s in c e c e n t e r a n dbo u n d a r ie so fd e f e c t sa r eb a r e l yd e t e c t e d .Toa v o idt h ist h ea d e q u a t es o l u t io nc o n s is t sinu s in gt h ec a me r a s a t u r a t io n .T h es a t u r a t io n h a s t h ee ¤e c to fin c r e a s in ga n yw h it eb l o b s in ima g e s .T h er e s u l to fs u c ha n e ¤e c t is t h a tt h e d e f e c td e t e c t io n in w h it e a r e a s is n o tpo s s ib l e a n y mo r e ,b u tita l l o w s t h e c o mp l e t e d e t e c t io n in b l a c ka r e a s o fa l lt h ep ix e l s b e l o n g in gt oad e f e c t .T h u s ,t h er e t a in e dt e c h n ic a ls o l u t io nf o rd e t e c t in gd e f e c t s o nh ig h l yr e ‡e c t iv eo bj e c t s c o n s is t s ina n a l y z in g t h e r e ‡e c t io n o fa l ig h t in gs y s t e m c o mpo s e d o fl a r g e ,‡a tb a c k -l ig h ts y s t e m o n w h ic h a t h in o p a q u e s t r ipe h a s b e e np l a c e ds ot h a t ,b yu s in gt h ec a me r as a t u r a t io n d e f e c t s o p t ima l l ya ppe a rf r o m t h eb l a c kb a c k g r o u n d .W ed e s c r ib eint h ef o l l o w in gs e c t io na nin d u s t r ia la p p l ic a t io n o fq u a l it yc o n t r o lt h a tu s e s t h is s pe c i…cl ig h t in g-0.1-0.0500.050.10.15Lighting Zs [mm]Xc [mm]F ig u r e9:po in t -t o -po in tr e l a t io n s h o w in gt h ed e f e c tp a r t s d e t e c t e du s in gt w ol ig h tt r a n s it io n sF ig u r e10:D e f e c tc a p t u r e db yt h ec a me r au s in gt w ol ig h tt r a n s it io n s0102030Number of pixelsStripe width[mm]3D E F E C T S L O C A L IZ A T IO NT h ed e f e c tl o c a l iz a t io n s y s t e m,b a s e do n k n o w l e d g eo ft h el ig h t in g,is n o wp r e s e n t e d.A s d e s c r ibe da b o v e, t h e l ig h ts o u r c eis c o mpo s e d o fl u min o u s t r a n s it io n.In o r d e rt od e t e c td e f e c t s o n ac y l in d r ic a ls h a peo bj e c t, ith a s be e n d e t e r min e d b y e x pe r ime n t s t h a tt h e l ig h ts o u r c emu s tb ec o mpo s e d o ft h r e e s t r ipe s,o n ed a r kin t h e mid d l e o ft w oh ig h l y l u min o u s.T h e s e n s ib il it y o ft h es y s t e m is in c r e a s e d b y u s in gt h es a t u r a t io n o ft h e c a me r a a s itis d is c u s s e d in t h e p r e v io u s s e c t io n.Co n s e q u e n t l y d e f e c t s o n l y a p pe a r s in d a r k s t r ipe s a s itis s h o w n in…g u r e12.T h eima g in gpr o c e s s in gd e v e l o pe df o re x t r a c t in gd e f e c t sf r o m ima g e smin imiz e st h ep r o c e s s in gt imeino r d e r t oa l l o wt h e v is io n s y s t e m t oma k e af a s td e c is io n a b o u tt h e r e j e c t io n o fd e f e c t iv e p r o d u c t s.Sin c e p r o d u c t s o n t h e irs u p po r tma y b e in v a r io u s po s it io n s,t h e…r s to pe r a t io n c o n s is t s in d e…n in ga w o r k in gw in d o wt h a t l imit s t h er e g io n o fin t e r e s tin w h ic h d e f e c t s mig h tb ep r e s e n t.T h is w o r k in gw in d o wl o c a t io n(s e e…g u r e12) is s ot h a titis a b o v et h epr o d u c ts u p po r t s,b e l o wt h ep r o d u c tt o p s,a n d it s s id e s a r ed e…n e d b yk n o w in gt h e o bj e c ts iz e.T h es u p po r t s a r ee a s il yd e t e c t a b l es in c et h e y k e e p t h es a mes h a pef o ra n yk in d o fp r o d u c tt ob e c o n t r o l l e d.T h es u p po r t s a p pe a rin t h el o w e rp a r to ft h eima g epr e s e n t e din…g u r e12.T h ef o l l o w in gima g ep r o c e s s in gc o n s is t s in…l t e r in gt h eima g eino r d e rt or e mo v et h en o is et h a tma yr e n d e r t h e d e f e c td e t e c t io n p r o c e s s in e¢c ie n t.A s mo o t h in ga l g o r it h m is u s e d f o rt h is p u r po s e.T h e l a s ta l g o r it h m a l l o w st h ed e t e c t io no ft h en u m b e ro fs t a t is t ic a lmo d e sin c l u d e dine a c hh o r iz o n t a lc r o s s-s e c t io no ft h eima g ea s w es e ein…g u r e13.T h ec r o s s-s e c t io na n a l y s is in d ic a t e s ad e f e c tift h r e es t a t is t ic a lmo d e s a r ec o u n t e d,in s t e a d o ft w omo d e s w it h o u td e f e c t.T h e mo d e c o u n t in gme t h o d is pe r f o r me d b y c o u n t in gt h e n u mb e ro fin‡e x io n po in t s in t h e s ig n a lo b t a in e d a f t e rt h e d e r iv a t io n o ft h e c r o s s-s e c t io n s ig n a l.P ix e l s b e l o n g in g t o d e f e c t s a r e e x t r a c t e d,a n dt h e nl a b e l l e dd u r in gt h is o pe r a t io n.F ig u r e14p r e s e n t s t h er e s u l to ft h el o c a l iz a t io npr o c e s s o f d e f e c t s.4C O M P L E T E IN D U ST R IA L SY ST E M T h ep r o d u c t s be in gc o n t r o l l e d a r er o t a t e dw h il ep a s s in gin f r o n to ft h ec a me r ain o r d e rt oa l l o wt h e irf u l l c o n t r o l.To d e c id e w h e t h e ro rn o ta p r o d u c tis d e f e c t iv e,t h e p ix e l s e x t r a c t e d f r o m e a c h w o r k in g w in d o w s a r e t h e n l a b e l e d.E a c h p ix e lb e l o n g in gt ot h e s a me d e f e c tw il lg e tt h e s a me l a b e l.T h e n u mb e ro fp ix e l s o f e a c h d e f e c ta n d t h e n u m b e ro fd e f e c t s a r e s t o r e d f o re a c h p r o d u c ta s itmo v e s in f r o n to ft h e c a me r a.T h is in f o r ma t io n is t h e n u s e d t oma k ead e c is io n a bo u tt h e q u a l it y o ft h e p r o d u c tb y c o mp a r in gitt oa c c e p t a n c e t h r e s h o l d s p r e v io u s l y d e c id e d b y t h e q u a l it y c o n t r o ld e p a r t me n t.T h e v is io n s y s t e m is e n d e d b y a p r o d u c t e x t r a c t io n mo d u l et h a te j e c t e s d e f e c t iv ep r o d u c t s f r o m t h ep r o d u c t io n l in e.T h ed e s c r ibe da u t o ma t e dt o o l,p r e s e n t e din…g u r e??,pe r f o r ms t h eq u a l it yc o n t r o lo fr e‡e c t iv ec y l in d r ic a l p r o d u c t sa tar a t eo fo n ep r o d u c tpe rs e c o n d.P r o d u c td is p l a c e me n ts pe e dise q u iv a l e n tt o5me t e r spe rmin u t e.A l lt h ep a r a me t e r s g iv e na b o v ea r el in k e dt op r o d u c t io nc o n s t r a in t s.T h is s y s t e m h a s be e nimp l e me n t e do n a 133M H z P C c o n n e c t e dt oaP CI f r a meg r a b be r.A s o f t w a r eh a s b e e n d e v e l o pe din b o t h a s s e m b l ya n dC++.D e f e c tl o c a l iz a t io n is ma d eo n d a t a‡o wa tt h er a t eo f50ima g e s pe rs e c o n d.F ig u r e15:Co mp l e t ein d u s t r ia ls y s t e mF ig u r e12:E x a mp l eo ff e wd e f e c t iv ep r o d u c t sF ig u r e13:a)H o r iz o n t a lc r o s s-s e c t io n in t h e ima g e w h e r e t h e r e is n od e f e c t.b)Cr o s s-s e c t io n in t h e ima g e w h e r et h e r eis ad e f e c t.5C O N C L U SIO NT h ea im o ft h is w o r kw a s t or e a l iz e da na u t o ma t e dq u a l it yc o n t r o lt o o lf o rw h ic ht h ek e yc o mpo n e n tis t h e r e a lt imec o n t r o lo fh ig h l yr e‡e c t iv e3do bj e c t s.T o r e a c h t h is g o a l,a s pe c i…c l ig h t in gs y s t e m h a s b e e n d e s ig n e d a n d a g e o me t r ic a lmo d e la l l o w e d u s t o d e…n e t h e o p t ima ls e to fp a r a me t e r s o ft h e v is io n s y s t e m s u c h a s t h e l o c a t io n o ft h e c a me r a w it h r e s pe c t t o t h e p r o d u c tt o be c o n t r o l l e d,a n d mo r e impo r t a n t l y,t h e o p t ima lc h a r a c t e r is t ic s o ft h e l ig h t in g s y s t e m.B a s e d o n t h is s t u d y,a t e c h n ic a ls o l u t io n f o rc o n t r o l l in gmo v in gr e‡e c t iv e o bj e c t s h a s be e n p r o po s e d.F a s t ima g ep r o c e s s in gh a v eb e e nd e v e l o pe da l l o w in gt h ec o mp u t a t io no fr e l e v a n tp a r a me t e r s s u c ha s t h en u m b e ro f d e t e t e d d e f e c t s a n d t h e n u m be ro fpix e l s o fe a c h d e f e c t.T h is in f o r ma t io n h a s b e e n c o mp a r e d t oa c c e p t a n c e t h r e s h o l d s in o r d e rt ow h e t h e ro rn o tc o n s id e rt h e p r o d u c ta s r e j e c t e d o ft h e p r o d u c t io n l in e.T h e c o mp l e t e v is io n s y s t e m p r o t o t y peh a s b e e n d e s c r ib e da n dita l l o w s t h ec o n t r o lo fo n ep r o d u c tw it h in o n es e c o n d.6R E F E R E N C E S[1]B.B a t c h e l o r,D.H il l,a n d D.H o d g s o n,A u t o ma t e d V is u a lIn s p e c t io n,IF S P u b l ic a t io n s L t d a n d N o r t hH o l l a n d,1985.[2]H.Je n d e r,Co n t rôl eTe mp sRée lP a rV is io nA r t i…c ie l l ed eT u b e sMét a l l iq u e sE nDé…l e me n tCo n t in u.T hés ed es c ie n c e s,U n iv e r s itéd eB o u r g o g n e,Ju in1993.[3]C.Co u l o t,S.Kh o l e r-H e mme r l in,C.D u mo n t,a n dB.L a ma l l e,“D ime n s io n a lc o n t r o lo fme t a l l ico bj e c t s b ya r t i…c ia lv is io n,”in P r o c.O fIE CO N96,p p.31–742,(T a ipe i(T A IW A N)),5-9A u g u s t1996.[4]D.A l u z e,C.Co u l o t,F.M e r ia u d e a u,P.G o r r ia,a n dC.D u mo n t,“M a c h in ev is io nf o rt h ec o n t r o l o fr e‡e c t in gn o np l a n es u r f a c e s,”in M a c h in eV is io nA p p l ic a t io ninIn d u s t r ia lIn s p e c t io n,p p.180–186,SP IE,(P it t s b u r g h (U SA)),15-17O c t199.[5]C.D u mo n t,F.T r u c h e t e t,D.A l u z e,a n d F.M e r ia u d e a u,“R e a lt ime c h a r a c t e r iz a t io n o fa s pe c t‡a w s o nw a r pe ds u r f a c eb ya r t i…c ia lv is io n,”O p t ic a lE n g in e e r in gJo u r n a l36,p p.2886–2896,O c t o b e r199.[6]D.A l u z e,C.D u mo n t,P.G o r r ia,a n dM.A.A b id i,“M a c h in ev is io nf o rc o n t r o l l in gr e‡e c t iv e3do bj e c t s,”inCo n f e r e n c eo nA p p l ie dM a c h in eV is io n,p p.45–62,So c ie t yo fM a n u f a c t u r in gE n g in e e r s,(N a s h v il l e(U SA)), M a y1998.[7]S.Kiy a s u,H.H o s h in o,K.Y a n o,a n d S.F u j imu r a,“M e a s u r e me n to ft h e3-d s h a pe o fs pe c u l a rpo l y e h e-d r o n s u s in ga nm-a r r a yc o de dl ig h ts o u r c e,”IEE E Tr a n s a c t io n s o n In s t r u me n t a t io n a n dM e a s u r e me n t44,p p.5–78,Ju n e1995.[8]D.Pér a r d a n d J.B r e y e r e r,“T h r e e-d ime n s io n a lme a s u r e me n to ff r e e-f o r ms s u r f a c e s w it h a s t r u c t u r e d-l ig h t in gr e‡e c t io n t e c h n iq u e,”in M a c h in e V is io n A p p l ic a t io n in In d u s t r ia lIn s p e c t io n,SP IE,(P it t s b u r g h (U SA)),15-17O c t o b e r199.[9]R.V a l k e n b u r ga n d A.M c Iv o r,“A c c u r a t e3d me a s u r e me n tu s in ga s t r u c t u r e d l ig h ts y s t e m,”Ima g e a n dV is io n Co mp u t in g16,p p.99–110,199.。
科学文摘
《科学文摘》简述 科学文摘》
内容 《科学文摘》主要报道由英国电气工程师 科学文摘》 学会的情报服务处搜集的文献， 学会的情报服务处搜集的文献，包括世界各国出 版的各种文字的期刊、科技报告、会议资料、 版的各种文字的期刊、科技报告、会议资料、图 论文和英美两国的专利说明书（1977年以 书、论文和英美两国的专利说明书（1977年以 后不再收录专利）。 后不再收录专利）。 各辑都按分类编排，1960年以前 年以前， 分类 各辑都按分类编排，1960年以前，采用国 际十进分类法编排。1961年改用自编的分类法 年改用自编的分类法。 际十进分类法编排。1961年改用自编的分类法。 1977年起 则按情报服务处、美国物理学会、 1977年起，则按情报服务处、美国物理学会、 年起， 英国物理学会、 英国物理学会、欧洲物理学会和国际科学协会理 事会文摘局共同编制的分类表编排。 事会文摘局共同编制的分类表编排。
查主题指南： 2008.2为例 查主题指南：以2008.2为例 control systems 1340, 3210P 确定分类号 1340 Specific control systems 1496 3210P Control systems 1542 得知3210P最切题，页码为1542。 得知3210P最切题，页码为1542。 最切题
科技英语阅读教程翻译 陈勇
Unit1 text A福岛的燕子我们对低剂量辐射对生物体和生态系统的影响知之甚少。
福岛核灾难四年后，科学家们开始得到一些答案。
By Steven Featherstone 直到1986年4月26日切洛贝利核电站的一个反应堆发生爆炸，在整个北半球扩散了相当于400枚广岛核弹的辐射尘，对于辐射对植被和野生动物的影响科学家几乎一无所知。
这场灾难创造了一个活生生的实验室，特别是在爆炸地点周围1100平方英里的地方，被称为禁区。
1994年，德克萨斯理工大学生物学教授罗纳德·切斯尔（Ronald Chesser）和罗伯特·贝克（Robert Baker）都是首批获准进入该区域的美国科学家。
我们抓到了一群田鼠，它们看起来像杂草一样健康。
贝克回忆说：“我们开始对它着迷。
当贝克和切斯对田鼠的DNA进行测序时，他们没有发现异常突变率。
他们还注意到，狼、猞猁和其他曾经稀有的物种在该区域游荡，仿佛它是一个原子野生动物保护区。
切洛贝利论坛由联合国一些机构于2003年成立，发表了一份关于切洛贝利利灾难20周年的报告，证实了这一观点，声称“环境改变对该地区的生物群产生了积极影响”，将其转变为“一个独特的生物多样性保护区”。
在Baker和Chesser对该地区进行田鼠研究的五年后，Timothy A.Mousseau 前往切洛贝利对鸟类进行了计数，发现了相互矛盾的证据。
南卡罗来纳大学生物学教授穆索和他的合作者现任巴黎南部大学生态，系统学与进化实验室的研究主任-- Anders Pape Moller，特别的研究了常见的乡村谷仓燕（Hirundo Rustica）。
他们发现该地区的燕子少得多，幸存下来的燕子寿命较短，生育力降低（男性），大脑较小，肿瘤，部分白化病（一种基因突变）和白内障发生率较高。
Mousseau 和Moller在过去13年发表的60多篇论文中表明，暴露于低水平辐射对该区域的整个生物圈（从微生物到哺乳动物，从虫子到鸟类）都有负面影响。
science[1]
![science[1]](https://img.taocdn.com/s3/m/a40361c02cc58bd63186bd6a.png)
An Investigation of the Pathology and Pathogens Associated with Porcine Respiratory DiseaseComplex in DenmarkM.S.Hansen *,†,S.E.Pors *,H.E.Jensen *,V .Bille-Hansen †,M.Bisgaard *,E.M.Flachs ‡and O.L.Nielsen **Department of Veterinary Disease Biology,Faculty of Life Sciences (LIFE),University of Copenhagen,Ridebanevej 3,DK-1870Frederiksberg C,†Department of Veterinary Diagnostics and Research,The National Veterinary Institute,Technical University of Denmark (DTU),Bu ¨lowsvej 27,DK-1790Copenhagen V and ‡National Institute of PublicHealth,University of Southern Denmark,Oster Farimagsgade 5A,DK-1399Copenhagen K,DenmarkSummaryRespiratory infections are among the most important diseases of growing pigs.In order to elucidate the multifactorial aetiology of porcine respiratory disease complex (PRDC)in Denmark,lungs from 148finishing pigs with cranioventral bronchopneumonia (case group)and 60pigs without lung lesions (control group)were collected from abattoirs.The pathogens involved in PRDC and their interactions were identified and linked to the histopathological diagnosis.The lung samples were cultured for bacteria and tested by multiplex polymer-ase chain reaction for presence of swine influenza virus (type A),porcine reproductive and respiratory syndrome virus (both European and US type),porcine circovirus type 2(PCV2),porcine respiratory corona-virus,porcine cytomegalovirus,Mycoplasma hyopneumoniae and Mycoplasma hyorhinis .All cases had cranioventral lobular bronchopneumonia consistent with PRDC.There was a broad range of microscopical lesions and the cases were characterized as acute (n ¼10),subacute (n ¼24)or chronic (n ¼114)bronchopneumonia.Five bacterial species,five viruses and two Mycoplasma spp.were detected in different combinations.PCV2,M.hyopneumoniae ,M.hyorhinis and Pasteurella multocida were detected most frequently among the PRDC affected swine and the diversity and number of pathogens were higher in these animals compared with controls.No clear-cut associations were detected between pathogens and histological lesions or histopathological diagnoses.PRDC occurs more frequently than enzootic pneumonia among Danish finishing pigs and has complex and varied histopathology.Ó2010Elsevier Ltd.All rights reserved.Keywords:bronchopneumonia;histopathology;pig;porcine respiratory disease complex (PRDC)IntroductionRespiratory infections constitute some of the most im-portant diseases of growing pigs and result in substan-tial economic losses and reduced welfare (Sørensen et al.,2006).Porcine respiratory disease complex (PRDC)is a multifactorial disease of finishing pigs from 14to 22weeks of age (Thacker,2001;Kim et al.,2003).Morbidity ranges from 10%to 40%and mortality from 2%to 20%(Harding and Hal-bur,2002;Harms et al.,2002).Lesions are primarily located in the cranioventral parts of the lung,where consolidation,discoloration and failure of the lung tis-sue to collapse may be observed (Harms et al.,2002).Histopathology may vary according to the pathogens involved,but bronchopneumonia,sometimes in com-bination with interstitial pneumonia,is often reported (Harms et al.,2002;Kim et al.,2003).In the USA,the most commonly isolated pathogens are porcine repro-ductive and respiratory syndrome virus (PRRSV),swine influenza virus (SIV),porcine circovirus type 2(PCV2),Pasteurella multocida and MycoplasmaCorrespondence to:M.S.Hansen (e-mail:mesi@win.dtu.dk ).0021-9975/$-see front matter Ó2010Elsevier Ltd.All rights reserved .doi:10.1016/j.jcpa.2010.01.012p.Path.2010,Vol.143,120e 131Available online at /locate/jcpahyopneumoniae.Other important pathogens associated with PRDC are Streptococcus suis,Actinobacillus pleuro-pneumoniae and[Haemophilus]parasuis(Thacker, 2001;Harms et al.,2002;Choi et al.,2003).A study from1999showed that25%of Danishfinishing pigs had cranioventral bronchopneumonia(CBP)at slaughter(Christensen and Enoe,1999).Concurrent abattoir surveys in Switzerland and Belgium showed a similar prevalence(Grest et al.,1997;Maes et al., 2001),whereas earlier surveys revealed a higher prev-alence,from37%in Canada(Osborne et al.,1981), 45%in Australia(Davies et al.,1992)to78%in an-other Canadian study(Wilson et al.,1986).Abattoir surveys of porcine bronchopneumonia usually focus on the gross pathology and/or the microbiology, whereas the histopathology and microbiology are sel-dom linked.A survey of the pathogens involved in CBP in Danish pigs has not been performed for de-cades and since new respiratory viruses(i.e.PCV2, porcine respiratory coronavirus[PRCV],PRRSV and new strains of SIV)have been identified in recent years,a survey of respiratory pathogens in this species has become relevant.The aims of the present study were to elucidate the complexity of pathogens involved in PRDC and their interactions infinishing pigs,and to associate these findings with the histopathological diagnosis,in order to broaden the understanding of the pathogenesis of porcine pneumonia.Materials and MethodsAnimalsDuring spring2006and winter2007,lungs,including tracheobronchial lymph nodes,from148finishing pigs with CBP(cases)and60pigs without gross lung lesions(controls)were collected from two Danish abattoirs in Zealand and Jutland.Cases of CBP were defined as those with lesions affecting a minimum of three cranioventral lung lobes(i.e.the apical,cardiac and intermediate lobes;Sørensen et al.,2006).The gross lesions were of acute and chronic inflammation and included consolidation,swelling,hyperaemia, failure to collapse and/orfibrosis.The samples were cooled and processed(see below)within5h of sam-pling.Tracheobronchial lymph nodes were not ob-tained from two animals with CBP andfive control animals.Gross PathologyLungs and tracheobronchial lymph nodes were eval-uated macroscopically and the morphological pat-tern,type of exudate and estimated duration of the pulmonary lesions were recorded.A preliminary diagnosis was made based on these observations. The bronchopneumonia was of the lobular type as evidenced by sharp(lobular)delineation between lesional and non-lesional tissue.Acute lesions were oedematous,hyperaemic and swollen.Subacute lesions were those in which swelling and hyperaemia were no longer present,but in these cases there may still have been mild oedema and often marked exuda-tion into the bronchi.Chronic lesions were character-ized by atelectic,fibrotic and grey-red lung tissue with dilation of exudate-filled bronchi.Lymph nodes were scored according to their size as normal(0),moderate enlargement(1)or marked enlargement(2). HistopathologyTissue samples were taken from lung lesions(cases), lung tissue of normal appearance from the dorsal sur-face of the right diaphragmatic lobe(all controls)and from the right apical lobe(20controls).The samples werefixed in10%neutral buffered formalin for24h, embedded in paraffin wax,sectioned(3e5m m)and stained with haematoxylin and eosin(HE).Tissue sections for immunohistochemistry(IHC)were mounted on SuperFrostÒPlus slides(Mensel-gla ser, Braunschweig,Germany).Selected sections were stained by Masson’s trichrome and phosphotungstic acid haematoxylin to detectfibrin and collagen. IHC for cytokeratin(Soerensen et al.,2005)was ap-plied to confirm the presence of epithelial hyperplasia, hyperplasia of type II pneumocytes and atelectasis. Sections were examined systematically by evalua-tion of the following structures in each section:bron-chi,bronchioles and bronchus-associated lymphoid tissue(BALT);alveolar ducts and alveoli,including alveolar septa;peribronchial,peribronchiolar and in-terlobular connective tissues;and pleura.BALT hy-perplasia was graded as follows(Ross,1999):(0) absent;(+)mild diffuse infiltration of lymphocytes in the peribronchial,peribronchiolar and perivascu-lar tissues including the lamina propria of the airways; (++)moderate increased diffuse infiltration of lym-phocytes and/or presence of a few lymphoid nodules; (+++)marked number of lymphoid nodules;or (++++)extensive number of lymphoid nodules af-fecting most of the lung section(Fig.1a e d).Alveolar exudates were classified according to Bochsler and Slauson(2002)as suppurative(neutrophils domi-nated),non-suppurative(mononuclear inflammatory cells dominated)or mixed(intermediate grades be-tween suppurative and non-suppurative;Fig.1e e g). Hyperplasia of type II pneumocytes was present when these cells lined more than3%of the alveolar surface area(Plopper and Adams,2006)(Fig.1h). Crowding of type II pneumocytes in close proximityPorcine Respiratory Disease Complex121Fig.1.Porcine lung tissue with different histological lesions found in cases of CBP.(a)Mild BALT hyperplasia (+)showing diffuseinfiltration of lymphocytes (arrows)into the peribronchial,peribronchiolar and perivascular tissues including the lamina propria of the airways.B,bronchiole;V,blood vessel.HE.Bar,250m m.(b)Moderate BALT hyperplasia (++)showing greater diffuse in-filtration of lymphocytes and/or the presence of a few lymphoid nodules (N).B,bronchiole.HE.Bar,250m m.(c)Marked BALT hyperplasia (+++)showing a considerable number of lymphoid nodules (N).B,bronchiole.HE.Bar,250m m.(d)Extensive BALT hyperplasia (++++)showing an extensive number of lymphoid nodules (N)affecting most of the lung section.A com-pressed bronchiole (B)can be seen.HE.Bar,250m m.(e)Suppurative alveolar exudates showing a cellular infiltrate dominated by neutrophils in acute suppurative bronchopneumonia (ASBP).HE.Bar,25m m.(f)Non-suppurative exudates showing a cellular infiltrate dominated by mononuclear inflammatory cells in chronic non-suppurative bronchopneumonia (CNBP).HE.Bar,25m m.122M.S.Hansen et al .to the interlobular connective tissue was not consid-ered a significant lesion.Acute lesions were defined as those with neutrophils as the dominant inflamma-tory cell type,extensive oedema and/orfibrin exuda-tion and absence of chronic signs.Chronic lesions were characterized byfibroplasias,BALT hyperpla-sia(of grade++to++++),hyperplasia of bron-chial or bronchiolar epithelium,presence of bronchiolar polyps and alveolar polyp-like structures with afibrous core,hypertrophy of the smooth muscle layer around bronchioles and alveolar ducts,and cel-lular infiltrates primarily consisting of lymphocytes and plasma cells.Lesions that were not strictly acute or chronic(e.g.cellular infiltration dominated by neutrophils,combined with moderate BALT hyper-plasia as the only chronic lesion)were regarded as subacute.Thus,the extent of acute versus chronic signs determined the duration of the inflammatory re-sponse.The histopathological diagnosis was regarded as the definitive diagnosis.MicrobiologyBacterial Culture.Swabs from lung lesions(cases)and from macroscopically normal lung tissue of the right diaphragmatic lobe(controls)were taken under ster-ile conditions,plated on blood agar plates(blood agar base CM55;Oxoid,Basingstoke,UK;with5%calf blood)and incubated aerobically in a sealed plastic bag at37 C for18e24h.All samples were cross-inoc-ulated with a v-factor producing Acinetobacter calcoaece-ticus.Bacterial isolates were identified using standard methods for phenotypic characterization as previously described(Barrow and Feltham,1993).Growth of P. multocida was evaluated semi-quantitatively according to the number of bacterial colonies on the primary plates:(+)weak growth with1e25colonies,(++) dense growth with25e300colonies or(+++) marked growth with>300colonies.Streptococcus spp. were differentiated by pulsed-field gel electrophoresis and strains representing different genotypes were identified by sequencing16S rRNA(Chadfield et al., 2004).All v-factor-dependent cultures were also sub-jected to16S rRNA sequencing to obtain afinal iden-tification.Mixed cultures demonstrating less than25 colonies were regarded as contamination. Mycoplasma and Virus Detection by Polymerase Chain Reac-tion.Tissue samples from lung lesions(cases)and macroscopically normal lung tissue(controls)were frozen atÀ20 C and investigated by multiplex poly-merase chain reaction(PCR;PulmotestÒ,Landesla-bor Schleswig-Holstein,Food,Veterinary and Environmental Diagnostic Institute of Schleswig-Holstein,Neumu nster,Germany),according to the method described by Palzer et al.(2007).Pathogens detected by the multiplex PCR were:SIV(influenza A),PRRSV(both European and US type),PCV2, PRCV,porcine cytomegalovirus(PCMV),M.hyop-neumoniae and Mycoplasma hyorhinis.StatisticsData were analyzed statistically by Chi-square test or by Fisher’s exact test when a small sample size necessi-tated this.The analysis of number of pathogens in rela-tion to lesion duration was carried out as a Poisson regression.The degree of association was estimated by Spearman-rho factor.All analyses were done with SAS version9.1(SAS Institute,Inc.,Cary,North Car-olina)with significance of P<0.05.Statistical analysis was not carried out on groups that included less than nine pigs and for this reason the results for PRRSV Eu-ropean and US types were pooled.When looking for as-sociations between pathogens or combination of pathogens and lesion duration,type of exudate or histo-pathological diagnosis,we tested against the remaining cases of CBP,excluding the control animals.ResultsGross PathologyThe gross lesions of all lungs in the case group(n¼148) were consistent with cranioventral,lobular broncho-pneumonia(Fig.2a).Mucopurulent,purulent or seromucous exudates were found in7%(11/148) acute,18%(26/148)subacute and75%(111/148) chronic cases of CBP,respectively.Focal or multifocal fibrotic pleurisy of the diaphragm lobes,without any relation to the pneumonic lesions,was present in 36%(54/148)of these animals.Except for13% (8/60)of the control pigs,which had chronic focal pleurisy,none of the controls had gross lesions.No gross lesions were detected in the lymph nodes in ani-mals from either group.Lymph node scores for the cases of CBP were:score0,3%(4/146);score1,66% (96/146);and score2,32%(46/146)and for the con-trol pigs:score0,62%(34/55);score1,35%(19/55); and score2,4%(2/55).A significant association was present between lymph node enlargement and CBP (P<0.001).When the lymph node scores were compared with the lesion duration(data not shown), no significant association was found(P¼0.16).(g)Mixed exudates showing cellular infiltrate with both neutrophils and mononuclear cells in subacute mixed bronchopneumonia (SMBP).HE.Bar,25m m.(h)Marked hyperplasia of type II pneumocytes.More than50%of the alveolar surface is lined by type II pneumocytes.IHC.Bar,25m m.Porcine Respiratory Disease Complex123Fig.2.Porcine lung tissue with different lesions.(a)Gross appearance of chronic CBP.Inset shows lung tissue with a bronchial pattern ofpulmonary consolidation.(b)Suppurative bronchiolitis and concurrent epithelial hyperplasia (E).HE.Bar,25m m.(c)Oedem-atous flooding of alveoli.HE.Bar,50m m.(d)Thickening of alveolar septa by collagenous (blue)tissue.Masson’s trichrome.Bar,50m m.(e)Alveolar polyp-like structures,P1with a fibrinous core and P2with cellular infiltrate.Both are covered by type I and type II pneumocytes as shown by immunohistochemical labelling for cytokeratin expression.Bar,25m m.(f)Alveolar polyp-like structure (P)with a collagenous core (blue).Masson’s trichrome.Bar,15m m.(g)Focal necrotic encapsulated tissue with central mineralization (M).HE.Bar,100m m.(h)Mild thickening of alveolar septa from a pig in the control group.HE.Bar,50m m.124M.S.Hansen et al .HistopathologyBased on the histopathological examination,the lungs in the case group(n¼148)were divided into acute (7%,10/148),subacute(16%,24/148)or chronic (77%,114/148)cases of bronchopneumonia(BP). The histopathological diagnosis(definitive diagnosis) for all of the acute cases(n¼10)was suppurative BP (ASBP).The subacute cases(n¼24)were subdivided into suppurative BP(SSBP)(67%,16/24),mixed BP (SMBP)(25%,6/24)or non-suppurative BP(SNBP) (8%,2/24),and the chronic cases(n¼114)were sub-divided into suppurative BP(CSBP)(46%,52/114), mixed BP(CMBP)(32%,37/114)or non-suppura-tive BP(CNBP)(22%,25/114).The main histopath-ologicalfindings are summarized in Table1. Microscopical lesions were found in the alveoli of all lungs with CBP.The majority also had lesions af-fecting bronchioles and/or alveolar ducts,often to-gether with lesions in the interlobular connective tissue.Bronchitis and bronchiolitis were mainly sup-purative,with concurrent epithelial hyperplasia in the subacute and chronic cases(Fig.2b).In cases of bronchiolitis,destruction of the epithelial lining in the bronchioles was observed in17%(1/6),50% (4/8)and37%(11/30)of the acute,subacute and chronic cases of CBP,respectively.The mainfinding in the alveoli was infiltration of inflammatory cells (neutrophils,lymphocytes and plasma cells),reflect-ing the duration of the inflammatory response, whereas macrophages were identified at all stages. Oedematousflooding was a commonfinding in the al-veoli in acute,subacute and chronic cases of CBP, with the degree of oedema being more pronounced in acute stages(Fig.2c).Varying degrees of thicken-ing of the alveolar septa,mainly by collagenous tissue, were seen in25%(37/148),of cases of CBP(Fig.2d). Alveolar polyp-like structures were seen in acute, subacute and chronic bronchopneumonia,whereas bronchiolar polyps only occurred in subacute and chronic lesions.Alveolar polyp-like structures with afibrinous core could be observed in both acute and chronic cases,whereas polyps consisting of collagen were not present in acute cases(Fig.2e,f).The major findings in the interlobular connective tissues were oedema,diffuse lymphocyte infiltration and/orfibro-plasia.Otherfindings included hypertrophy of the muscles around bronchioles and alveolar ducts and hyperplasia of type II pneumocytes.Occasionalfind-ings were vasculitis,thrombosis and areas of necrosis with or without mineralization(Fig.2g).Not all combinations of these lesions were seen in the lung sections.The lungs from three animals,diag-nosed as acute(n¼1)or subacute(n¼2)according to gross pathology,were definitely diagnosed as chronic on the basis of histopathology.Microscopical lungTable1Histopathologicalfindings in the lungs from control animals and cases of CBPControl CBP*(n¼60)Acute(n¼10)Subacute(n¼24)Chronic(n¼114)n%n%n%n% Bronchitis123303121412 Bronchiolitis126608333026 Bronchiolar polyps0e0e282118 BALT hyperplasia†04168440281412+15256604172623++470e16675246+++0e0e0e1211++++0e0e28109 Alveolar oedema1288018756759 Fibrin exudation into alveoli0e550729109 Type II pneumocyte hyperplasia353307294035 Thickening of alveolar septa16271108332825 Alveolar polyp-like structures0e2209383026 Smooth-muscle hyperplasia231103133127 Interstitial oedema2377010423430 Interstitialfibroplasia231105213430 Necrotic foci0e0e1487*Cases of CBP were grouped as acute,subacute or chronic based on histological evaluation.†Hyperplasia of the BALT was scored as absent(0),mild(+),moderate(++),marked(+++)or extensive(++++).Porcine Respiratory Disease Complex125lesions were seen in50%(30/60)of the control animals and no difference was observed between the samples from the diaphragmatic and the cranioventral lobes. Thefindings in these animals mainly included focal or multifocal thickening of alveolar septa(Fig.2h) and/or mild BALT hyperplasia(Table1). MicrobiologyA total of12potential pathogens(five bacterial spe-cies,five viruses and two Mycoplasma spp.)were de-tected and these are listed in Table2.In general, the frequencies of the pathogens were higher in the case group compared with controls,except for PCMV,which was more frequent in the controls (though not significant).PRCV was not detected in any of the pigs.Staphylococcus aureus,[H.]parasuis,A.pleuropneumoniae and SIV-A were only detected in one tofive animals.S.aureus,[H.]parasuis,A.pleuro-pneumoniae,PRRSV European and US type were only found in the cases of CBP.When comparing cases and controls according to pathogens(Table 2),all grades of P.multocida(P<0.001e P¼0.004), M.hyopneumoniae(P<0.001)and M.hyorhinis (P<0.001)were found more frequently in the cases of CBP.Furthermore,thefinding of mixed cultures and sterile samples was more frequent in the control group than in the case group(P<0.001).Significant associations were observed between eight pairs of pathogens among the diseased animals and between two pathogens in the control group(Table3).A total of63different combinations of pathogens were present,many of which were only found in a sin-gle animal(n¼34;data not shown).Among the casesTable2Bacterial culture and multiplex PCR for viruses and MycoplasmaPigs with CBP(n¼148)Control animals(n¼60)P value*Acute Subacute ChronicASBP (n¼10)SSBP(n¼16)SMBP(n¼6)SNBP(n¼2)CSBP(n¼52)CMBP(n¼37)CNBP(n¼25)n%n%n%n%n%n%n%n%Bacterial cultureP.multocida†+0e2131170e484116‡240e0.004 ++2205‡313‡5015051025312120.004 +++77085011715031601849104012<0.001 S.suis0x e4252330e713822624610NS S.aureus0e0e0e1500e0e0e0e NS [H.]parasuis0e0e0e0e2425140e NS A.pleuropneumoniae0e0e0e0e120e0e0e NS Mixed culture2200e0e0e0e4110e2745<0.001 Sterile0e0e0e0e510384162542<0.001 Multiplex PCRPCV21010014886100210050963710024965693NS PRRSVEU type1103190e0e2413140e NS US type0e0e0e0e120e0e0e NS PCMV3303191170e15297196242643NS SIV-A0e0e0e0e0e251412NS M.hyopneumoniae10100159461001505198359524962137<0.001 M.hyorhinis9901381610021004179308117682235<0.001Numbers and percentage of positive animals are listed for the148pigs with CBP in relation to diagnosis.ASBP,acute suppurative bronchopneumonia(BP);SSBP,subacute suppurative BP;SMBP,subacute mixed BP;SNBP,subacute non-suppurative BP;CSBP,chronic suppurative BP;CNBP,chronic non-suppurative BP;CMBP,chronic mixed BP.PRRSV(EU type,European type;US type, North American type);SIV-A,swine influenza virus type A;NS,not significant;PCV2,porcine circovirus type2;PCMV,porcine cytomegalo-virus.*P values for differences between cases and controls were calculated by either the Chi-square or Fischer’s exact test as appropriate.†Growth of P.multocida was graded as weak growth(+),dense growth(++)or marked growth(+++).‡The frequency of each pathogen detected in the diagnosis group was tested against the remaining cases of CBP by the Chi-square or Fischer’s exact test.Significant associations are marked by‘‡’.126M.S.Hansen et al.of CBP and the control animals there were51and23 different combinations of pathogens,respectively. The10most frequent combinations are presented in Table4.Some combinations were seen in either dis-eased or healthy animals.The three most frequent combinations,only isolated from cases of CBP,were combinations1,6and10(Table4).Likewise,the two most frequent combinations,only seen among the control animals,were mixed culture and PCV2, and PCV2as a solitary pathogen.Associations between Microbiological and Histopathological FindingsWhen testing associations of selected histological le-sions(bronchiolar polyps,BALT hyperplasia,fibrin exudation into alveoli,hyperplasia of type II pneu-mocytes,thickening of alveolar septa,alveolar polyp-like structures,necrotic foci)within the case group,and subsequently within lesion duration groups,to pathogens,significant results were ob-tained for the following:in chronic cases with bron-chiolar polyps,P.multocida(+++)was isolated more frequently(P¼0.016);BALT hyperplasia (grade++to++++)was associated with PCMV in chronic cases(P<0.001);fibrin exudation into alveoli was associated with the isolation of P.mul-tocida(++)(P¼0.018);thickening of alveolar septa was never seen when P.multocida(+)was isolated (P¼0.013).Furthermore,in78%(7/9)of cases with necrotic foci,P.multocida(+++)was present, although with an association of only borderline signif-icance(P¼0.062).No association between histologi-cal lesions and pathogens was found in the control group.Table2presents the frequencies of single patho-gens,divided according to the diagnosis groups. P.multocida was,as the only pathogen,isolated more frequently from the following groups:P.multocida (++)and SSBP(P¼0.054);P.multocida(++) and SMBP(P¼0.037);and P.multocida(+)and CNBP(P¼0.043).S.suis was not isolated from any case of ASBP(P¼0.021).Significant associations were not seen when comparing single pathogens and type of exudate(suppurative,mixed and non-suppu-rative)or lesion duration(acute,subacute and chronic).In Fig.3the number of pathogens detected in each pig is listed for the lesion duration groups and the con-trol group.At least one pathogen was detected in all lung samples(cases and controls).Detection of a singleTable3Significant associations between pairs of pathogens Associated pathogens P value*Spearman-rho factor Animals with CBP(n¼148)PCV2and P.multocida(+)†0.0170.067 PCV2and S.suis0.0210.088 PCV2and M.hyopneumoniae0.012À0.038 PCV2and PRRSV0.0130.048 PCV2and PCMV0.0250.104P.multocida(++)and M.hyorhinis0.0500.157S.suis and M.hyopneumoniae0.0220.097 PRRSV and M.hyopneumoniae0.0140.052 Control animals(n¼60)PCV2and S.suis0.0320.105*P values were tested by the Fischer’s exact test and the degree of association was calculated by the Spearman-rho factor-test.†Weak growth of P.multocida on the plate(+).Table4The10most frequent combinations of pathogensamong cases of CBP and control animalsCombination number12345678910 Mixed cultureÂP.multocida+ÂP.multocida++ÂP.multocida+++ÂÂÂS.suisÂPCMVÂÂÂPCV2ÂÂÂÂÂÂÂÂÂÂM.hyopneumoniaeÂÂÂÂÂÂÂM.hyorhinisÂÂÂÂÂÂFrequency of combination(n¼)*CBPAcute3e3†1e1e e e e Subacute4133e e e e e1 Chronic3398618e e34 Controls e4118e972eGrowth of P.multocida defined as weak(+),dense(++)or marked (+++).*Number of animals with a given combination of pathogens.†Significantassociation.Fig.3.The frequency of pathogen count detected in controlanimals(n¼60)and in animals with CBP of acute(n¼10),subacute(n¼24)or chronic(n¼114)type. Porcine Respiratory Disease Complex127pathogen(PCV2)occurred in seven animals,all from the control group.The majority of pigs in the control group had a significantly lower number of pathogens, while cases of CBP had increased counts(P<0.001). Between lesion duration groups there was a tendency to a lower count in the chronic cases compared with acute and subacute cases;however,this difference was not significant.When comparing the10most frequent combina-tions of pathogens and lesion duration groups(Table 4)the only significant association was combination number3,which was seen more frequently in the acute cases(30%,3/10)(P¼0.044)than in the sub-acute(13%,3/24)and chronic cases(7%,8/114). There were no significant associations when compar-ing these combinations of pathogens with types of ex-udate or histopathological diagnosis(data not shown).DiscussionPneumonia can be classified as embolic,broncho-pneumonia and interstitial or bronchointerstitial (Caswell and Williams,2007)based on the morpho-logical pattern observed in experimental studies and/or infections with single pathogens.The present study of naturally occurring pneumonia recorded a range of pneumonic lesions,but the predominant pattern was bronchopneumonia associated with thickening of the alveolar septa.In some animals chronic lesions were accompanied by acute lesions, which may represent the healing of acute pneumonic lesions or the presence of two different disease inci-dents.These cases of bronchopneumonia were also characterized microscopically according to the esti-mated duration of the disease process(i.e.as acute, subacute or chronic).Few previous studies have fo-cused on the histopathologicalfindings in porcine lungs with naturally occurring PRDC(Harms et al., 2002),whereas many studies describe naturally oc-curring gross lesions or the histopathology of experi-mental coinfections.The pigs examined by Harms et al.(2002)had clinical signs of respiratory disease and therefore the lesions observed in that study were more severe than in the pigs of the present investigation.The results of the present study show that the histo-pathology of PRDC is complex,as nearly all pulmo-nary reaction patterns can co-exist.Thickened alveolar septa were observed in pigs from both control and case groups,indicating that thisfinding is not en-tirely related to bronchopneumonia.This lesion may therefore be regarded as a pulmonary response to en-vironmental factors associated with swine production (e.g.dust and ammonia).Furthermore,thickening of alveolar septa was not associated with the presence of specific pathogens.Type II pneumocyte hyperplasia occurred more frequently in pigs with CBP compared with controls;however,the lesion did not appear to be associated with the duration of disease,since it was present in all diagnosis groups.In addition to the bronchiolar polyps in the pigs with pneumonic le-sions,there were also structures that resembled alveo-lar polyps,(i.e.they protruded from the epithelial surface in the alveoli and were covered by epithe-lium).Three different forms of alveolar polyp-like structures were identified(fibrinous,cell-infiltratedfi-brinous and collagenous)and these probably repre-sented different stages of the same initial lesion. Alveolar polyp-like structures have not been described previously in pigs and their significance is undetermined.Most authors define PRDC as a multifactorial re-spiratory disease involving several pathogens(Harms et al.,2002;Kim et al.,2003;Opriessnig et al.,2007; Fachinger et al.,2008),whereas Thacker(2006)spec-ifies PRDC as enzootic pneumonia(i.e.infection with Mycoplasma spp.and opportunistic bacteria)aggra-vated by respiratory viruses.Except for14animals, Mycoplasma spp.,bacteria and respiratory viruses were identified in all cases of CBP in the present study. This pathogen profile,combined with the pathologi-calfindings,is in accordance with the diagnosis of PRDC,although it is not possible to determine the or-der of infection.Based on the pathogen combination,‘classical’enzootic pneumonia was only present infive animals with CBP,which indicates that PRDC is more prevalent in Danishfinishing pigs compared with enzootic pneumonia.This probably corresponds to thefindings in other countries,where a mixture of Mycoplasma spp.,bacteria and viruses are identified in the majority of porcine pneumonias(Harms et al., 2002;Kim et al.,2003;Palzer et al.,2007).Twelve different pathogens were obtained from the lungs and the spectrum of pathogens correlated with observations made in other countries(Chiou et al., 2004;Palzer et al.,2008).The following potential pathogens(Thacker,2001;Liljegren et al.,2003) were only present in the case group:S.aureus,[H.]par-asuis,A.pleuropneumonia and PRRSV(European and US type).Therefore,these agents might represent more aggressive pathogens in cases of PRDC,al-though the difference in frequency between cases and controls was not significant.The diversity and number of pathogens were higher among the diseased animals compared with the control group,supporting the definition of PRDC as a multifactorial disease (Harms et al.,2002),which should be considered when diagnosing and treating cases of PRDC and in prophylactic strategies.The observed tendency128M.S.Hansen et al.。
【精品】科技英语阅读课文翻译unit19
科技英语阅读1—9单元译文：Unit1罗素悖论的提出是基于这样的一个事例：设想有这样一群理发师，他们只给不给自己理发的人理发。
假设其中一个理发师符合上述的条件，不给自己理发；然而按照要求，他必须要给自己理发.但是在这个集合中没有人会给自己理发。
（如果这样的话，这个理发师必定是给别人理发还要给自己理发）1901年,伯特兰·罗素悖论的发现打击了他其中的一个数学家同事。
在19世纪后期,弗雷格尝试发展一个基本原理以便数学上能使用符号逻辑。
他确立了形式表达式(如：x=2）和数学特性（如偶数）之间的联系.按照弗雷格理论的发展，我们能自由的用一个特性去定义更多更深远的特性。
1903年，发表在《数学原理》上的罗素悖论从根本上揭示了弗雷格这种集合系统的局限性。
就现在而言,这种类型的集合系统能很好的用俗称集的结构式来描述.例如，我们可以用x代表整数，通过n来表示并且n大于3小于7，来表示4,5，6这样一个集合。
这种集合的书写形势就是：x={n：n是整数,3〈n<7}。
集合中的对象并不一定是数字。
我们也可让y={x：x是美国的一个男性居民}。
表面上看，似乎任何一个关于x的描述都有一个符合要求的空间。
但是，罗素(和策梅洛一起)发现x=｛a：a不再a中｝导致一个矛盾，就像对一群理发师的描述一样。
x它本身是在x的集合中吗？否定的答案导致了矛盾的出现。
当罗素发现了悖论,弗雷格立即就发现悖论对他的理论有致命的打击。
尽管这样，他还不能解决这个问题，并且上世纪有很多的尝试，去解决这个问题（但没有成功）。
罗素自己对这个悖论的回答促进了类型理论的形成。
他解释说，悖论的问题在于我们混淆了数集和数集的集合。
所以，罗素介绍了对象的分级系统:数、数集、数集的集合等等.这个系统为形式化数学的形成奠定了基础,至今它还应用于哲学研究和计算机科学分支。
策梅洛对于罗素悖论的解决方法用新的公理：对于任意公式A（x）和任意集合b，都会有一个集合满足y={x：x既在b中又满足A(x)｝取代了以前的公理:对于任意公式A（x），都会有一个集合满足y={x：x满足A（x）}。
《科学》杂志精选（2012.02.10）
《科学》杂志精选（2012.02.10）1. 关于创新2. 俄罗斯计划研制福布斯－土壤2火星探测器3. 能够自愈的高分子材料4. 远古西伯利亚“人族”个体的基因组公布5. 显微镜下的美图要登上时代广场6. 日本开始拥抱私人科研捐赠7. 最新研究认为细菌DNA不会吸收砷作为基本成分8. 法国“常青藤”9. 室内生态系统冠状动脉中的凝块电镜扫描图片1. 关于创新这句英文原文是：CREATIVEIDEAS ARE CHILDREN OF SOLITUDE, YET ARE RARELY CONCEIVED IN ISOLATION.我翻译的版本是：创意来自个人，转化要靠大家。
2. 俄罗斯计划研制福布斯－土壤2火星探测器俄罗斯科学院航天研究所所长列夫·泽廖内1日说，俄打算研制与去年11月发生事故的“福布斯－土壤”火星探测器类似的新航天器——“福布斯－土壤2”，并计划在2018年将其送往火星的卫星。
泽廖内在新闻发布会上说，由于携带的科研设备可能有所减少，“福布斯－土壤2”项目的费用将少于“福布斯－土壤”探测器项目，约为30亿卢布(约合1亿美元)。
新航天器仍由拉沃奇金科研生产联合体研制。
泽廖内表示，之所以选择2018年发射“福布斯－土壤2”是因为这一年地球和火星间的距离最短。
另据专家预测，届时俄航天工业水平将大大提高，从而更有利于完成火卫探测任务。
“福布斯－土壤”探测器是近15年来俄实施的唯一火星探测项目，其主要目的是从火卫一采集土壤样本运回地球，中国首个火星探测器“萤火一号”也搭载于其上。
去年11月9日，探测器在发射后未能进入预定轨道，并于两个多月后坠落在太平洋海域。
俄航天署日前表示，事故原因可能是太空射线使航天器机载计算系统失灵。
3. 能够自愈的高分子材料这种材料用刀切开后，还能自己愈合。
4. 远古西伯利亚“人族”个体的基因组公布WIKI：丹尼索瓦人（Denisovahominin）是人属的一个古人类化石，可能在更新世晚期生活于亚洲大陆。
nature09171
LETTERSRegulation of myeloid leukaemia by the cell-fate determinant MusashiTakahiro Ito 1*,Hyog Young Kwon 1*,Bryan Zimdahl 1,Kendra L.Congdon 1,Jordan Blum 1,William E.Lento 1,Chen Zhao 1,Anand Lagoo 2,Gareth Gerrard 3,Letizia Foroni 3,John Goldman 3,Harriet Goh 4,Soo-Hyun Kim 4,Dong-Wook Kim 4,Charles Chuah 5,Vivian G.Oehler 6,Jerald P.Radich 6,Craig T.Jordan 7&Tannishtha Reya 1Chronic myelogenous leukaemia (CML)can progress from a slow growing chronic phase to an aggressive blast crisis phase 1,but the molecular basis of this transition remains poorly understood.Here we have used mouse models of CML 2,3to show that disease progression is regulated by the Musashi–Numb signalling axis 4,5.Specifically,we find that the chronic phase is marked by high levels of Numb expression whereas the blast crisis phase has low levels of Numb expression,and that ectopic expression of Numb promotes differentiation and impairs advanced-phase disease in vivo .As a possible explanation for the decreased levels of Numb in the blast crisis phase,we show that NUP98–HOXA9,an oncogene assoc-iated with blast crisis CML 6,7,can trigger expression of the RNA-binding protein Musashi2(Msi2),which in turn represses Numb.Notably,loss of Msi2restores Numb expression and significantly impairs the development and propagation of blast crisis CML in vitro and in vivo .Finally we show that Msi2expression is not only highly upregulated during human CML progression but is also an early indicator of poorer prognosis.These data show that the Musashi–Numb pathway can control the differentiation of CML cells,and raise the possibility that targeting this pathway may provide a new strategy for the therapy of aggressive leukaemias.Chronic myelogenous leukaemia (CML)is initiated by the BCR–ABL translocation,which leads to myeloid cell expansion while allow-ing differentiation 8–11.Secondary translocations such as NUP98–HOXA9or AML1–EVI1,or mutations in p53or INK4A/ARF,trigger progression through an accelerated phase to a blast crisis phase,with progressive loss of the capacity to differentiate 1.Although blast crisis CML is,in part,more aggressive because of arrested differentiation,the pathways that underlie this arrest remain poorly understood.To determine whether CML progression may be driven by reversal of signals that regulate differentiation during normal development,we focused on Numb 4,a molecule that can be inherited differentially during asymmetric division and specify a committed fate 12–16.To determine whether Numb regulates leukaemia progression we used mouse models representing chronic phase and myeloid blast crisis CML.Chronic disease was generated by infecting haematopoie-tic stem-cell-enriched populations (c-Kit 1Lin 2Sca-11or KLS)with BCR–ABL and transplanting them into irradiated recipient mice 2,3.Myeloid blast crisis was modelled by transplanting KLS cells trans-duced with BCR–ABL and NUP98–HOXA9(refs 6,7,17).Using these we found that Numb was expressed at significantly lower levels in the blast crisis phase compared with the chronic phase (Fig.1a–c).The decreased expression of Numb in the blast crisis phase indicatedthat keeping Numb at low levels may be essential for maintaining an immature state and that increasing its levels could trigger differenti-ation and inhibit disease progression.To test this possibility,haema-topoietic cells were infected with BCR–ABL and NUP98–HOXA9together with either control vector or Numb,transplanted and leuk-aemia progression monitored.A total of 83%of control mice developed leukaemia compared with 63%of those transplanted with Numb-expressing cells (Fig.1d).Notably,leukaemias that developed in the presence of Numb were more differentiated (Fig.1e,f)and unable to propagate disease efficiently (93%versus 20%,Fig.1g)or infiltrate secondary organs (Fig.1h,i and Supplementary Fig.1);no signs of leukaemia were detected in mice that survived (Fig.1j and Supplementary Fig.1).Numb also impaired propagation of fully established leukaemias and markedly reduced the frequency of can-cer stem cells (Supplementary Fig.2).These data show that continual repression of Numb is essential for maintenance of blast crisis CML,and that increasing the levels of Numb can inhibit disease.Because Numb can antagonize Notch signalling in several sys-tems 13,18,19,we tested whether Numb and Notch had a reciprocal relationship in CML.Notch signalling was elevated in blast crisis CML (Supplementary Fig.3),and its inhibition via dominant nega-tive Xenopus Suppressor of Hairless (dnXSu(H))delivery or through conditional deletion of Rbpj paralleled the effects of Numb and led to reduced incidence and propagation of blast crisis CML (Supplementary Fig.4).Furthermore,levels of p53,another Numb target 20,were higher in Numb-expressing blast crisis CML (Supplementary Fig.5a).In the absence of p53,Numb was unable to affect leukaemic cell growth in vivo or in vitro (Supplementary Fig.5b–f),indicating that Numb’s effects are in part dependent on p53.The observation that Numb repression was critical for the main-tenance of blast crisis CML led us to seek the mechanism by which Numb may be downregulated in this context.We focused on the RNA-binding protein Musashi (Msi),which has been shown in the nervous system to repress Numb by binding the 39untranslated region (UTR)of the transcript 21.Msi was originally identified in Drosophila as a regulator of asymmetric division 5,22and its expression has been associated with stem and progenitor cells in several tis-sues 23,24.In the haematopoietic system we found that Msi2was expressed at much higher levels than Msi1(Fig.2a),and was particu-larly elevated in stem cells (Fig.2b).Paralleling this,Msi2expression was tenfold higher in the more immature blast crisis CML (Fig.2c);this pattern held true even in matched lineage-negative fractions (Fig.2d),indicating that Msi2upregulation in the advanced phase*These authors contributed equally to this work.1Department of Pharmacology and Cancer Biology,Duke University Medical Center,Durham,North Carolina 27710,USA.2Department of Pathology,Duke University Medical Center,Durham,North Carolina 27710,USA.3Department of Haematology,Imperial College London,Hammersmith Hospital,London W120NN,UK.4Division of Hematology,Seoul St Mary’s Hospital,The Catholic University of Korea,Seoul,Korea.5Department of Haematology,Singapore General Hospital,Cancer and Stem Cell Biology Program,Duke-NUS Graduate Medical School,Singapore.6Clinical Research Division,Fred Hutchinson Cancer Research Center,Seattle,Washington 98109,USA.7James P.Wilmot Cancer Center,University of Rochester School of Medicine,Rochester,New York 14642,USA.Vol 466|5August 2010|doi:10.1038/nature09171765is not simply a consequence of altered cellular composition.Finally,expression of Msi2was most enriched in the lineage-negative fraction of blast crisis CML (Fig.2e).These data indicate that Msi2expression associates predominantly with normal haematopoietic stem cells and the most immature fraction of leukaemic cells.Because Msi2and Numb were expressed in a reciprocal pattern,we tested whether Msi2could repress Numb during leukaemogenesis.Expression of Msi2in chronic phase CML cells led to downregulation of Numb (Fig.2f,g).Furthermore,NUP98–HOXA9could also activate this cascade by increasing expression of Msi2(Fig.2h).Because NUP98–HOXA9initiates transformation through HoxA9-mediated DNA binding and transcription,we tested whether HoxA9could bind the Msi2promoter and activate its expression directly.Chromatin immunoprecipitation revealed that HoxA9was associated with the putative HoxA9-binding element we identified at 25.7kb (Fig.2i–l).NUP98–HOXA9expression was also able to induce Msi2reporter activity in KLS cells (Fig.2m and Supplementary Fig.6a).These data show that Msi2can be upregulated by NUP98–HOXA9and sub-sequently contribute to blast crisis CML by repressing Numb.To test if Msi2is required for the development of blast crisis CML,we used a mouse in which the Msi2gene was disrupted by a gene-trap (Gt)vector 25(Supplementary Fig.6a,b).Msi2mutant mice were viable,albeit smaller and less frequent than predicted (Msi21/1:Msi21/Gt :Msi2Gt/Gt 538:66:19,P 50.038),and showed a two–three-fold reduction in the frequency (Fig.3a)and absolute number (data not shown)of KLS cells.Additionally,loss of Msi2led to significantly impaired leukaemia growth in vivo (Fig.3b,93%for control versus 57%for Msi2Gt/Gt ).To determine whether inhibiting Msi2could have an impact on the growth of established CML,and to rule out the possibility that the reduced incidence of leukaemia in gene-trap mutants was due to developmental defects,Msi expression was targeted using an alterna-tive short hairpin (sh)RNA approach (Supplementary Fig.7a).Delivery of Msi2shRNAs (shMsi)into established blast crisis CML cells increased Numb expression (data not shown)and reduced leuk-aemia growth in vitro (Fig.3c and Supplementary Fig.7b–e)and in vivo (Fig.3d).Further,the majority of leukaemias that occurred in the presence of shMsi were more differentiated (Fig.3e)and impaired in their ability to propagate disease (Fig.3f,88%control versus 25%shMsi).These data show that Msi2is important for the establishment and continued propagation of blast crisis CML.Finally,we examined whether MSI2was aberrantly upregulated during human leukaemia progression.MSI2was tracked in 30patient samples from repositories in Korea and the United Kingdom,and found to be expressed at significantly higher levels in blast crisisMsi1Msi2Tbpa b c d efij klg hmW B M K L S C h r o n i c B l a s t c r i s i s O B –R T W a t e rControl Msi28006004002000R e l a t i v e M s i 2 e x p r e s s i o n600400200000204060501001502002500100200300R e l a t i v e M s i 2 e x p r e s s i o nR e l a t i v e M s i 2 e x p r e s s i o n 400300200100R e l a t i v e M s i 2 e x p r e s s i o nK L SB l as t cr i s i s Ch r o n i cB la s t cr i s i s L i n –Ch r o n i c L i n –B l as t c r i s i s L i n –B l a s t c r i s i s L i n +L i n +K L SL i n +F l u o r e s c e n c e i n t e n s i t y (a .u .)R e l a t i v e M s i 2 e x p r e s s i o nCo n t r o l Co n t r o l NUP 98–H O X A 9Co n t r o l NUP 98–H O X A 9M s i 2*********~430 kb+110 kb–5.7 kb1214Murine Msi2 gene 5,0004,0003,0002,0001,0000β-G a l a c t o s i d a s e a c t i v i t y (a .u .)Flt3 promoter Experiment 2Experiment 1Experiment 1Experiment 2I n p u t I g G A n t i -H o x A 9I n p u t I g G A n t i -H o x A 9I n p u t I g G A n t i -H o x A 9+1Figure 2|The RNA-binding protein Musashi is highly expressed in immature normal and leukaemic cells and is regulated by HoxA9.a ,Musashi (Msi)expression in whole bone marrow (WBM),KLS cells,chronic and blast crisis CML,olfactory bulb (OB),2reverse transcriptase (2RT in OB)and water.Tbp,TATA-binding protein.b –e ,Real-time RT–PCR analysis of Msi2expression in KLS cells (n 53)and Lin 1cells (n 52)(b ),blast crisis phase (n 59)and chronic phase (n 56)(c ),Lin 2chronic and blast crisis phase cells relative to normal KLS and Lin 1cells (Lin 1,n 52and others,n 53)(d ),and Lin 2(n 55)or Lin 1(n 55)blast crisis CML cells (e ).Error bars represent s.e.m.;*P 50.039;**P ,0.001.f ,g ,Control vector-or Msi2-expressing CML cells were stained with anti-Numb antibody (red)and DAPI (greenpseudocolour)(f ),and fluorescence intensity was quantified (g ).**P ,0.001.h ,Msi2expression in KLS cells transduced with either control vector or NUP98–HOXA9retrovirus along with BCR–ABL.*P 50.017.i –l ,HoxA9binds to the Msi2promoter.Murine Msi2gene structure:numbered boxes indicate exons;transcription start site (TSS)and the direction of transcription are indicated by 11and the black flag,respectively;the oval indicates putative HOX binding element 5.7kb upstream of TSS;the open rectangle indicates 1110kb site with no HoxA9binding sequence.ChIP was performed either with IgG control or anti-HoxA9antibody for Flt3,a known HoxA9target gene,as a positive control (j ),and for Msi225.7kb region (k )or Msi21110kb region (l ).m ,KLS cells from Msi2gene-trap reporter mice were transduced with BCR–ABL and either control vector or NUP98–HOXA9,and b -galactosidase reporter activity was quantified (n 52each;*P 50.011).a.u.,arbitrary units.adgehijfb c Chronic Blast crisis12080406040200F l u o r e s c e n c e i n t e n s i t y (a .u .)7550NumbGapdhC h r o n i c B l a s t c r i s i sC h r o n i c Co n t r o l N u m b B l a s t c r i s i sLineageNumbNumb NumbControlControlControlNumb (40 days)Numb (150 days)Control35.61.54R e l a t i v e c e l l n u m b e rP e r c e n t s u r v i v a lP e r c e n t s u r v i v a l100755025010075502500255010012575Days elapsed 0255010012515017575Days elapsedL i n – (%)***PrimarySecondarykDaFigure 1|Expression of Numb impairs blast crisis CML development.a ,b ,CML cells were immunostained with anti-Numb antibody (red)and 49,6-diamidino-2-phenylindole (DAPI,green pseudocolour)(a ),and fluorescence intensity was quantified,*P ,0.05(b ).a.u.,arbitrary units.c ,CML cells were analysed by western blot for Numb expression.d ,Cells infected with BCR–ABL,NUP98–HOXA9and either control vector or Numb were transplanted and survival was monitored (control,n 518;Numb,n 519).e ,f ,Representative (e )and average frequency of Lin 2cells (f )from control or Numb expressing leukaemias.**P ,0.001.g ,Donor-derived cells from primary leukaemias were serially transplanted and survival monitored (vector,n 514;Numb,n 515;**P ,0.001).h –j ,Haematoxylin-and-eosin-stained spleen sections from control vector (h )or Numb expressingleukaemias (i )or surviving mice (j ).Immature myeloid cells (red arrowheads)and lymphoid follicles (black arrowheads)are indicated.Originalmagnification,310.Error bars in all bar graphs are s.e.m.Data shown are representative of three to four independent experiments.LETTERS NATURE |Vol 466|5August 2010766CML (Fig.4a,b).To determine if this reflected a general pattern in human CML progression,we examined the expression of MSI2and associated genes in 90patient samples from banks in the United States 26.Microarray analysis revealed a marked upregulation of MSI2in every patient during CML progression (Fig.4c).Furthermore,NUMB was downregulated in a majority of blast crisis patients (Fig.4d).Notably,our mouse model was driven by NUP98–HOXA9as a second hit,whereas human blast crisis CML patients harbour a variety of secondary mutations.Because Msi2could be regulated by HoxA9expression in the mouse model of CML,we examined whether HOXA9was upregulated in blast crisis CML samples.The observation that a majority of patient samples had elevated levels of HOXA9(Fig.4e)may explain how MSI2becomes upregulated in advanced stage disease regardless of the nature of the second hit.Notch signalling targets HES1and TRIB2were also elevated in a number of blast crisis patient samples (Fig.4f and Supplementary Fig.8),consistent with other independent reports 27.Because the highest MSI2expression was observed in blast crisis patients,where treatment outcomes are extremely poor,and because a range of expression was observed in both chronic and accelerated phase CML,we tested whether MSI2expression correlated with out-come after allogeneic transplantation.Patients were divided into two groups based on median expression of MSI2.Among 37chronic phase patients with available outcomes (9relapses),increased MSI2expression was associated with a higher risk of relapse (hazard ratio 54.35;95%confidence interval,0.90–21.06,P 50.07).Additionally,among 13accelerated phase patients with available out-comes (6deaths and 3relapses),increased MSI2expression was notonly associated with higher risk of relapse (all relapses occurred in the increased MSI2group,P 50.06)but also with higher risk of death (hazard ratio 56.76;95%CI,0.78–58.57,P 50.08).The association of MSI2with poorer outcomes indicates that MSI2may be an early marker of advanced CML disease.Our work identifies the Musashi–Numb axis as an important regu-lator of myeloid leukaemia and indicates that maintenance of the immature state is dependent on reversal of classical differentiation cues.Specifically,we find that MSI2is upregulated and NUMB down-regulated as chronic phase CML progresses to blast crisis,and that modulation of this pathway can inhibit disease (Fig.4g).Although previous work has implicated Musashi and Numb in normal develop-ment 13,14,23,24,to our knowledge this is the first demonstration that this pathway is required for haematological malignancy.Our previous work showing that whereas BCR–ABL cannot affect the choice between asymmetric and symmetric division,NUP98–HOXA9can trigger a bias towards symmetric renewal 15,had led us2001501005000.200.400.600.801.001.20–0.20–0.400.00R e l a t i v e g e n e e x p r e s s i o n200150100500R e l a t i v e g e n e e x p r e s s i o n****abcde gf Ch r o n i cC h r o n i c A c c e l e r a t e d B l a s t c r i s i sC h r o n i c A c c e l e r a t e d B l a s t c r i s i sCh r o ni cA cc el er at edB l as t cr i si sCh r o n i c A c c e l e r a t e d B l a s t c r i s i sB la s t c r i s i sCh r o n i cB la s t c r i s i sMSI2NUMBE x p r e s s i o n v a l u e0.300.600.901.201.501.80–0.60–0.30–0.90–1.200.00E x p r e s s i o n v a l u e0.300.600.901.201.50–0.60–0.300.00E x p r e s s i o n v a l u e–0.40–0.200.000.200.400.60–0.80–1.00–0.60E x p r e s s i o n v a l u eHOXA9HES1First hitBCR–ABLSecond hitNUP98–HOXA9AML1–EVI1, p53Chronic phaseBlast phaseDifferentiationProliferation SurvivalMSI2NUMBMSI2NUMBFigure 4|Musashi expression is upregulated duringhuman CML progression.a ,b ,PCR analysis of MSI2expression in chronic and blast crisis CML patient samples from the Korean Leukaemia Bank,Korea (n 59per cohort,Mann–Whitney U -test,**P ,0.001)(a ),and the Hammersmith MRD Lab Sample Archive,United Kingdom (n 56per cohort,Mann–Whitney U -test,**P ,0.001)(b ).Error bars represent s.e.m.c –f ,Microarray analysis of expression of MSI2(c ),NUMB (d ),HOXA9(e )(all P ,0.001)and HES1(f )(P 50.68)in bone marrow and peripheral blood samples from 42chronic (red),17accelerated(green)and31blastcrisisphase(blue)patientsintheUnited States.g ,Proposed model for the role of MSI2and NUMB in CML progression.c -K i tScal3.09% 1.85% 1.78%Lin – gatedabe fcd75501004030201002500102030Days elapsed40506070P e r c e n t s u r v i v a lC o l o n y n u m b e r7550100250P e r c e n t s u r v i v a l 7550100250010203040506070Days elapsedDays elapsed0102030405060708090100P e r c e n t s u r v i v a lMsi2Gt/Gt Msi2+/+Msi2+/+Msi2+/GtMsi2Gt/Gt**PrimarySecondaryshMsi shMsiControlControlshMsiControlshLuc shMsiFigure 3|Loss of Musashi impairs the development and propagation of blast crisis CML a ,Representative FACS plots showing frequency of KLS cells in mice of the indicated genotypes (Msi21/1,n 54;Msi21/Gt ,n 53;Msi2Gt/Gt ,n 54).b ,Survival curve of mice transplanted with BCR–ABL-and NUP98–HOXA9-infected Msi21/1or Msi2Gt/Gt KLS cells (Msi21/1,n 515;Msi2Gt/Gt ,n 514;*P 50.0159).c ,Colony-forming ability of blast crisis CML cells transduced with control shRNA (shLuc)or Msi2shRNA (shMsi).Error bars represent s.e.m.**P ,0.001.d ,Survival curve of micetransplanted with established blast crisis CML cells infected with control shLuc or shMsi (n 513each;*P 50.0267).e ,Wright’s stain of leukaemic cells from mice transplanted with control shLuc-or shMsi-infected blast crisis CML.Immature myeloblasts,filled arrowheads;differentiating myelocytes and mature band cells,open arrowheads.Originalmagnification,3100.f ,Survival curve of mice transplanted with Lin 2cells from primary shRNA-expressing leukaemias (n 516each;**P ,0.001).Data shown is representative of two to three independent experiments.NATURE |Vol 466|5August 2010LETTERS767to propose that regulators of asymmetric division might regulate leukaemic differentiation,and could thus be targets for therapy in advanced myeloid leukaemia.Our current work supports this and shows that Numb,which drives commitment and differentiation,can impair blast crisis CML establishment and propagation.It should be noted that just as Numb’s influence may be mediated through p53 and/or Notch signalling12,13,20,Musashi may act through Numb as well as other targets such as p21WAF1(refs21,28).Because blast crisis CML is uniformly resistant to current treat-ments,it is critical to identify new pathways that drive this aggres-sive disease.In that context,our work is important because it shows that specific differentiation cues associated with the Musashi–Numb cascade can unlock the differentiation potential of blast crisis CML and impair its growth.These data,together with the fact that Musashi seems to be anearly marker of advanced CML,indicate that its expression could serve as a prognostic tool,and that target-ing it might represent a new approach to therapy.Finally,reports of increased expression of Musashi in glioblastoma29and decreased expression of NUMB in high-grade breast cancer30raise the possibility that this pathway may also be relevant in solid cancers. METHODS SUMMARYMouse models of CML were generated by transducing bone marrow stem and progenitor cells with retroviruses carrying BCR–ABL(chronic phase)or BCR–ABL and NUP98–HOXA9(blast crisis phase)and transplanting them into irra-diated recipient mice.The development of CML was confirmed by flow cyto-metry and histopathology.For Msi2knockdown experiments,lineage-negative blast crisis CML cells were infected with Msi2or control Luciferase shRNA retroviral constructs and leukaemia incidence monitored.Chromatin immuno-precipitation(ChIP)assays were performed using the myeloid leukaemia cell line M1.DNA was crosslinked and immunoprecipitated with control or anti-HOXA9antibodies and analysed by PCR for regions of interest.CML patient samples were obtained from the Korean Leukaemia Bank(Korea),the Hammersmith MRD Lab Sample Archive(United Kingdom),the Fred Hutchinson Cancer Research Center(United States)and the Singapore General Hospital(Singapore).Gene expression in human chronic and blast crisis CML was analysed by PCR or by DNA microarrays.Full Methods and any associated references are available in the online version of the paper at /nature.Received7August2008;accepted13May2010.Published online18July2010.1.Calabretta,B.&Perrotti,D.The biology of CML blast crisis.Blood103,4010–4022(2004).2.Daley,G.Q.,Van Etten,R.A.&Baltimore,D.Induction of chronic myelogenousleukemia in mice by the P210bcr/abl gene of the Philadelphia chromosome.Science247,824–830(1990).3.Pear,W.S.et al.Efficient and rapid induction of a chronic myelogenous leukemia-like myeloproliferative disease in mice receiving P210bcr/abl-transduced bone marrow.Blood92,3780–3792(1998).4.Uemura,T.,Shepherd,S.,Ackerman,L.,Jan,L.Y.&Jan,Y.N.numb,a generequired in determination of cell fate during sensory organ formation in Drosophila embryos.Cell58,349–360(1989).5.Nakamura,M.,Okano,H.,Blendy,J.A.&Montell,C.Musashi,a neural RNA-binding protein required for Drosophila adult external sensory organ development.Neuron13,67–81(1994).6.Mayotte,N.,Roy,D.C.,Yao,J.,Kroon,E.&Sauvageau,G.Oncogenic interactionbetween BCR-ABL and NUP98-HOXA9demonstrated by the use of an in vitro purging culture system.Blood100,4177–4184(2002).7.Dash,A.B.et al.A murine model of CML blast crisis induced by cooperation betweenBCR/ABL and NUP98/HOXA9.Proc.Natl A99,7622–7627(2002).8.Witte,O.The role of Bcr-Abl in chronic myeloid leukemia and stem cell biology.Semin.Hematol.38,3–8(2001).9.Ren,R.Mechanisms of BCR-ABL in the pathogenesis of chronic myelogenousleukaemia.Nature Rev.Cancer5,172–183(2005).10.Melo,J.V.&Barnes,D.J.Chronic myeloid leukaemia as a model of diseaseevolution in human cancer.Nature Rev.Cancer7,441–453(2007).11.Goldman,J.M.&Melo,J.V.BCR-ABL in chronic myelogenous leukemia–howdoes it work?Acta Haematol.119,212–217(2008).12.Knoblich,J.A.Mechanisms of asymmetric cell division during animaldevelopment.Curr.Opin.Cell Biol.9,833–841(1997).13.Spana,E.P.&Doe,C.Q.Numb antagonizes Notch signaling to specify siblingneuron cell fates.Neuron17,21–26(1996).14.Shen,Q.,Zhong,W.,Jan,Y.N.&Temple,S.Asymmetric Numb distribution iscritical for asymmetric cell division of mouse cerebral cortical stem cells and neuroblasts.Development129,4843–4853(2002).15.Wu,M.et al.Imaging hematopoietic precursor division in real time.Cell Stem Cell1,541–554(2007).16.Wang,H.,Ouyang,Y.,Somers,W.G.,Chia,W.&Lu,B.Polo inhibits progenitorself-renewal and regulates Numb asymmetry by phosphorylating Pon.Nature 449,96–100(2007).17.Neering,S.J.et al.Leukemia stem cells in a genetically defined murine model ofblast-crisis CML.Blood110,2578–2585(2007).18.Justice,N.,Roegiers,F.,Jan,L.Y.&Jan,Y.N.Lethal giant larvae acts together withnumb in notch inhibition and cell fate specification in the Drosophila adult sensory organ precursor lineage.Curr.Biol.13,778–783(2003).19.Wakamatsu,Y.,Maynard,T.M.,Jones,S.U.&Weston,J.A.NUMB localizes inthe basal cortex of mitotic avian neuroepithelial cells and modulates neuronal differentiation by binding to NOTCH-1.Neuron23,71–81(1999).20.Colaluca,I.N.et al.NUMB controls p53tumour suppressor activity.Nature451,76–80(2008).21.Imai,T.et al.The neural RNA-binding protein Musashi1translationally regulatesmammalian numb gene expression by interacting with its mRNA.Mol.Cell.Biol.21,3888–3900(2001).22.Okabe,M.,Imai,T.,Kurusu,M.,Hiromi,Y.&Okano,H.Translational repressiondetermines a neuronal potential in Drosophila asymmetric cell division.Nature411, 94–98(2001).23.Sakakibara,S.et al.RNA-binding protein Musashi family:roles for CNS stem cellsand a subpopulation of ependymal cells revealed by targeted disruption andantisense ablation.Proc.Natl A99,15194–15199(2002).24.Okano,H.et al.Function of RNA-binding protein Musashi-1in stem cells.Exp.CellRes.306,349–356(2005).25.Taniwaki,T.et al.Characterization of an exchangeable gene trap using pU-17carrying a stop codon-b geo cassette.Dev.Growth Differ.47,163–172(2005). 26.Radich,J.P.et al.Gene expression changes associated with progression and responsein chronic myeloid leukemia.Proc.Natl A103,2794–2799(2006). 27.Nakahara,F.et al.Hes1immortalizes committed progenitors and plays a role in blastcrisis transition in chronic myelogenous leukemia.Blood115,2872–2881(2010).28.Battelli,C.,Nikopoulos,G.N.,Mitchell,J.G.&Verdi,J.M.The RNA-bindingprotein Musashi-1regulates neural development through the translationalrepression of p21WAF-1.Mol.Cell.Neurosci.31,85–96(2006).29.Liu,G.et al.Analysis of gene expression and chemoresistance of CD1331cancerstem cells in glioblastoma.Mol.Cancer5,67(2006).30.Pece,S.et al.Loss of negative regulation by Numb over Notch is relevant to humanbreast carcinogenesis.J.Cell Biol.167,215–221(2004).Supplementary Information is linked to the online version of the paper at /nature.Acknowledgements We thank A.M.Pendergast,J.Chute,K.Itahana,L.Penalva and L.Grimes for advice and reagents;K.-i.Yamamura for the Msi2gene-trap mice; T.Honjo for the Rbpj conditional mice;N.Gaiano for the TNR mice;D.Baltimore for the lentiviral shRNA constructs;and A.Means and B.Hogan for comments on the manuscript.We also thank M.Cook,B.Harvat and L.Martinek for cell sorting; M.Fereshteh for advice on analysis of patient samples;D.McDonnell and H.Wade for advice on ChIP experiments;S.W.Tian for help in collecting patient samples and A.Chen and S.Honeycutt for technical help.The BCR–ABL construct was a gift from W.Pear and the NUP98–HOXA9construct a gift from G.Gilliland.T.I.is the recipient of a postdoctoral fellowship from the Astellas Foundation for Research on Metabolic Disorders,K.L.C.is the recipient of an American Heart Association predoctoral award,B.Z.received support from T32GM007184-33and T.R.is the recipient of a Leukemia and Lymphoma Society Scholar Award.This work was also supported by an LLS Translational Research grant and an ASH Junior Faculty Award to V.G.O.,as well as NIH grants CA18029to J.P.R.,CA140371to V.G.O., CA122206to C.T.J.and DK63031,DK072234,AI067798,HL097767,DP1OD006430and an Alexander and Margaret Stewart Fund grant to T.R.We are grateful for the support received from the Lisa Stafford Research Prize.Author Contributions T.I.and H.Y.K.designed the research,performed the majority of the experiments and helped write the paper.B.Z.,K.L.C.,J.B.,W.E.L.and C.Z.provided experimental data and help;A.L.provided histopathological analysis;C.T.J.,G.G.,L.F.,J.G.,H.G.,S.-H.K.,D.-W.K.and C.C.provided human patient samples and experimental advice;T.I.,H.Y.K.,G.G.and B.Z.defined gene expression in patient samples by PCR;and V.G.O.and J.P.R.carried out all microarray and patient outcome analyses.T.R.conceived of the project,planned and guided the research,and wrote the paper.Author Information Reprints and permissions information is available at/reprints.The authors declare competing financial interests: details accompany the full-text HTML version of the paper at / nature.Readers are welcome to comment on the online version of this article at /nature.Correspondence and requests for materials should be addressed to T.R.(t.reya@).LETTERS NATURE|Vol466|5August2010 768。
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