The case for RAMCloud by John Ousterhout, Parag Agrawal, David Erickson, Christos Kozyrakis, Jacob Leverich, David Mazières, Subhasish Mitra, Aravind Narayanan, Diego Ongaro, Guru Parulkar, Mendel Rosenblum, Stephen M. Rumble, Eric Stratmann, and Ryan Stutsman CACM july 2011 | vol. 54 | no. 7 remark: With scalable high-performance storage entirely in DRAM, RAMCloud will enable a new breed of data-intensive applications. 1 RAMCloud Overview 2 Motivation the two styles of applications in Figure 1. 2.1 Scalable storage for existing applications. NoSQL 2.2 Technology trends. 2.3 Research Challenges The case for RAMCloud.pdf
背景： Prof. Sterns 是耶鲁大学知名进化生物学家，本学期在北大开设Key Issues in Evolut ion 和 Principles of Evolution 两门课程，总计40余名学生。 在12月初，有一位学生交的期 末论文中发现明显剽窃，为此教授公开宣布判此人零分并致函所有同学以示告诫。 而所有论文都递交之后，又发现两人有严重剽窃行为。教授因此非常伤心，致函如下： To my students in Beijing, Fall 2007: While grading papers today I encountered two more cases of plagiarism. One was sophisticated but serious. The other was so blatant that it was almost unbelievable. That makes a total of three students who have failed my courses because of plagiarism. 今天批阅论文的时候，我又遇到了两例剽窃行为。一例手法老练但是情节严重，另一例则是厚颜无耻得令人难以置信。这样总计就有三名学生因为剽窃而在我的课程中不及格。 If I had not warned you and given you the opportunity honestly to correct your essays, there would have been several more. I thank those of you who were honest and showed me what you had copied. 假如我前些时候没有警告过你们，并给你们一次机会去诚实地改正你们的文章，这种事情还会多好几例。有些同学诚实地告诉了我他们都抄袭了哪些部分，我向他们表示感谢。 Plagiarism disturbs me greatly, both because it corrodes my relationship with you as my students, and because it tells me things about China and Beida that neither you nor I want to hear. 这些剽窃行为让我非常苦恼，不但因为它损害了你我之间的师生关系，也因为它告诉了我一些关于北大、关于中国的事情，而这些事情是你我都不愿意听到的。 It corrodes my relationship with you because I work hard to be a good teacher, I take time to prepare good lectures, and I spend many hours providing detailed feedback on essays. It is hard work. You cannot imagine what it is like to correct the details of the 500th essay until you have done it yourself. I do that to help you learn to think more clearly, to express yourself convincingly, and to develop your intellectual power, your ability to understand the world. I also do it because I value you, I value your ideas, and I think the world will be a better place when you can all think clearly and behave intelligently. Later in life, some of you will be leaders with important positions. I want you to be competent and honest, for I have seen too often what terrible things can happen when leaders are incompetent and dishonest. Leadership aside, I want all of you to be able to create value in your lives, whatever you end up doing, and you cannot do that if you deceive. 它伤害了我们之间的关系，因为我为了当一名好老师而付出了许多努力。我花了许多时间准备课堂讲授，又花了许多时间给你们的文章写下详尽的反馈。这些工作都很辛苦。你无法想象，当改到第500篇文章的细节的时候你是什么感觉，除非你亲身经历。我做这一切，是为了让你们学会更清晰地思考问题，学会有说服力地表达自己的观点，学会培养自己的理性，锻炼自己理解世界的能力。我做这一切，也因为我珍视你们，珍视你们的想法，而且我想，如果你们都能够清晰地思考、明智地行动的话，这个世界也会变得更加美好。在以后的人生道路里，你们当中有的人会成为身居要位的领导，我希望你们能够德才均备，因为无德无才的领导者所能带来的可怕灾难，我已经见过太多了。就算不当领导，我也希望你们所有人都能在你们的生命中创造一些有价值的东西，无论你们最后从事什么。而如果你欺骗的话，你是做不到这一点的。 When a student whom I am teaching steals words and ideas from an author without acknowledgment, I feel cheated, dragged down into the mud. I ask myself, why should I teach people who knowingly deceive me? Life is too short for such things. There are better things to do. 当我所教的学生从别人那里偷窃话语和思想的时候，我感到受了欺骗，心情沉重如同跋涉泥沼。我会问自己，我为什么要给那些存心欺骗我的人上课呢？生命是如此的短暂，太不值得。有比这好得多的事情可以做。 Disturbingly, plagiarism fits into a larger pattern of behavior in China. Cxiaoneinternational intellectual property rights. Beida sees nothing wrong in copying my textbook, for example, in complete violation of international copyrightagreements, causing me to lose income, stealing from me quite directly. No one in China seems to care. I can buy DVDs in stores and on the street for about one US dollar. They cost $20-30 outside China; the artists who produced them are losing enormous amounts of stolen income, billions of dollars each year. China has become notorious for producing defective products that have to be recalled because the pose health threats to consumers. A recent cartoon in an American newspaper shows the Central Committee reacting to an accusation that they have violated human rights. The response? "Wait until they see what we put in their toothpaste next!" Corruption is a serious problem in a booming economy. For example, in the mining industry, about 5000 miners die each year and mine owners cut corners in violation of the law. The social fabric breaks when workers die because owners are greedy. The Mandate of Heaven is lost. 让人不安的是，剽窃已经成为整个中国行为模式的一部分。中国忽视国际知识产权。比如说，复印我的书彻头彻尾违反了国际版权协议，使我损失了收入，对我而言近乎直接的偷窃，然而北大人却对此安之若素。再比如，我只花大约一美元就能在街头和店铺买到DVD光碟，这些碟片在别国要卖上二三十美元。创作它们的艺术家因此损失的大笔收入全是被偷走的，每年几十亿。因为生产劣质商品对消费者造成潜在的健康威胁而不得不召回，中国已经是臭名昭著了。最近美国报纸上刊载的一幅漫画描绘了中央委员会被指责侵犯人权。猜他们怎么回答？“往他们牙膏里搁点东西，看他们还敢吭声不？”经济繁荣的背后，腐败已经成为严重的问题。就拿矿业来说，每年大约有五千名矿工死去，就因为矿主为了省事为了利润而不惜违反法律 。(译注：cut corners 指贬义的抄近道，此为意译。)矿主的贪婪导致工人死去，象征着社会阶层之间纽带的断裂。天道已丧。 China appears to have lost her way. Confucius said, do not do to others what you do not want them to do to you. He also said, a gentleman is honest. Honesty and reciprocity are the basis of trust and community. We cannot get along in a world filled with deceit and defection; such a world becomes a Hobbesian war of all against all, nasty and brutal. We cannot do science if we cannot trust what others publish. There is no reason to try to replicate a result if it cannot be trusted. It would not be worth the effort.Without replication there can be no shared knowledge that is tested and trustworthy -that is, no science. Without science, there can be no technology. And without technology, there can be no steady increase in productivity, economic growth, and a better life for all. 中国似乎已经迷失了她的道路。孔子说过，己所不欲勿施于人。他还说过，人而无信不知其可。(直译是君子有信，不过一时想不起原话是怎么说的了。) 诚实互惠是信任与社群的基础。在一个充满欺诈和背叛的社会中，我们无法生存，这样的世界成了霍布森(是他吧？哲概的东西快忘干净了)式的“每个人与每个人为敌”的战争，险恶而野蛮。若是我们不能相信别人发表的东西，我们就没法做科研。谁都没有理由去企图重复一个不可信的结果，不值得费那功夫；而没有重复就不会有经过验证而可信靠、可共享的知识，也就没有科学。没有科学就不会有技术，没有技术就不会有生产力的稳步发展，经济水平的持续增长，也就不会给所有人都带来更美好的生活。 The penalties for plagiarism that you will encounter later in life are very serious. If you do it as a graduate student, you can be expelled from university, and you will not get your degree. If you do it as a faculty member, you can lose your job. I know you may not believe that, for the sociology professor at Beida who translated an entire book into Chinese and published it with his name on it only lost his administrative positions but kept his professorship and salary. But things are not like that elsewhere . When plagiarism is detected in the United States, it can end the career of the person who did it. That is also true in Europe. 在你们今后的人生里，剽窃将会遇到极为严厉的惩罚。身为研究生如果剽窃，就会直接开除，没有学位。身为教员如果剽窃，就会丢掉饭碗。我知道你们可能不信，因为北大那位把整本书翻成中文就署上自己名字出版的社会学家 (这是谁啊...) 仅仅丢了行政职务，却仍然保有教授之位和薪水。然而事情在别处并非如此。在美国如果发现有人剽窃，此人的职业生涯可以就此毁于一旦。欧洲亦然。 The fact that I have encountered this much plagiarism at Beida tells me something about the behavior of other professors and administrators here. They must tolerate a lot of it, and when they detect it, they cover it up without serious punishment, probably because they do not want to lose face. If they did punish it, it would not be this frequent. 我在北大遇见了如此之多的剽窃，这一事实说明了其它教授和行政官员的所作所为。他们必然是对此颇为容忍，而当发现有人剽窃时，他们未加严厉惩罚就遮掩过去，很可能是因为他们不愿丢脸。假如他们真的施以惩罚，剽窃决不会这么猖獗。 I have greatly enjoyed teaching some of you. I have encountered young minds here that are as good as any in the world. Many of you are brave, most of you work very hard, most of you are honest, and some of you are brilliant. But I am leaving with very mixed feelings. It is quite sad that so many promising young Chinese think it is necessary to cheat to succeed. They damage themselves even more than the people from whom they steal and the people whom they deceive with stolen words. 给你们当中一些人上课的时候，我感受到了极大的喜悦。我在这里遇到的年轻的头脑，和世界上任何地方比起来都毫不逊色。你们当中许多人都很勇敢，大部分人都很努力，大部分人都很诚实，有些人相当聪明。然而当我离去时，心情是复杂的。这么多前途无量的中国年轻人认为要靠作弊才能成功，让我十分伤心。比起那些被他们窃走思想的人，和那些被他们用窃来的的话语所欺骗的人，他们伤害得还要多的，是他们自己。 Sincerely, Steve Stearns Updated Friday 2:28 a.m. A Yale biology professor who taught at Peking University this fall as part of a joint program between the two schools has accused the Chinese school of turning a blind eye toward plagiarism, raising questions about the academic integrity of an institution that is a central partner in Yale’s internationalization efforts. Ecology and Evolutionary Biology professor Stephen C. Stearns ’67 sent a passionate, 958-word statement to his students at Peking this month, bemoaning the rampant cheating he witnessed while teaching two courses at the university. In his message, Stearns said he was “leaving with very mixed feelings” because of the behavior he had observed. “The fact that I have encountered this much plagiarism … tells me something about the behavior of other professors and administrators here,” Stearns wrote. “They must tolerate a lot of it, and when they detect it, they cover it up without serious punishment, probably because they do not want to lose face. If they did punish it, it would not be this frequent.” Launched in 2006, the Peking University–Yale University Joint Undergraduate Program allows Yale students to spend a semester living and studying with Peking University students on the school’s Beijing campus. Through the program Yale students take classes in English with Peking University and Yale faculty and receive full course credit at Yale. Stearns’ e-mail raises questions about whether Peking University’s courses are as rigorous as Yale’s. Allegations of plagiarism at Yale nearly always result in a hearing before the Executive Committee, the College’s student disciplinary body. Students found guilty typically face probation, suspension or expulsion, assistant Yale College dean and ExComm Secretary Jill Cutler told the News in September. In an e-mail message to the News on Sunday, Stearns said he has been inundated with over 100 e-mails from China and beyond regarding his message, which he said was originally intended as advice for his students at Peking, not for a wider audience. His missive has since been posted in English and in Chinese on several Chinese Web sites and was the subject of a report on the Web site of the Chronicle of Higher Education last week. Stearns said he allowed his students to post the message online because they thought it would be helpful to students elsewhere. In his e-mail, Stearns said three students in his courses this fall received failing grades for plagiarism. Rampant academic dishonesty “fits into a larger pattern of behavior in China” that includes widespread sale of pirated DVDs and a disregard for international intellectual property standards, he added. Stearns said in the letter one Peking University sociology professor who copied an entire book into Chinese and published it in his own name did not lose his job when he was caught. “China ignores international intellectual property rights,” Stearns said. “ sees nothing wrong in copying my textbook, for example, in complete violation of international copyright agreements, causing me to lose income, stealing from me quite directly. No one in China seems to care.” In a message circulated at Peking University, the dean of the College of Life Sciences at Peking, Yi Rao, vowed that any faculty member he has hired since assuming his position would be fired if found to have been academically dishonest. “We do encounter many problems,” Rao said in his message, “but it is the hope for an increasingly better future that keep us working to improve the university, to make it great in one day when it contributes more to the world than it takes from the world.” “We will regain our long held tradition of honesty and trust,” he said. Stearns, meanwhile, said he met with senior administrators at Peking before returning to the United States last month and was assured the university would take his feedback to heart. “They told me that they took plagiarism very seriously and are going to work actively to reduce it,” he said, adding, “Their stance is constructive and gives hope.” But the professor is not the only one to raise questions about academic integrity at Peking University. In an e-mail message, a Yale senior, who studied abroad through the Peking program last spring said the university “definitely” had a more relaxed attitude toward plagiarism than Yale. The student, who asked to remain anonymous, said he and another Yalie who participated in the program both witnessed overt acts of plagiarism while at Peking. “All of both witnessed and heard about … acts of plagiarism,” said the senior. “We had Chinese partners in many of our classes who would take excerpts from books without notating them or changing them in any way.” Copying and pasting from Internet sources was also common, the student said. Students were never told they could not lift material word-for-word and present it as their own, the student said. Academic corruption is widespread across China, according to experts on higher education in China. Fang Shi-min, a Chinese molecular biologist and de facto plagiarism watchdog, told the Chronicle last year that he has tracked nearly 500 cases of plagiarism and other forms of misconduct at the country’s leading universities, which he chronicles on a Web site devoted to the subject. And last year, more than 100 top academics across the country signed an open letter urging Chinese officials to crack down on academic corruption “Even when a case is exposed,” Fang told the Chronicle, “the university will usually try to cover it up — particularly when the accused is a big shot — to protect the fame and gain of the university.” Yale administrators who oversee the Peking University–Yale University Joint Undergraduate Program could not immediately be reached for comment. Peking University, sometimes called “the Harvard of China,” has a student body of about 30,000, including 15,000 undergraduates. It is also a member of the International Alliance of Research Universities, the ten-school consortium of which Yale was a founding member. 注释：本文转自《耶鲁新闻报》（Yale News，作者：Thomas Kaplan）
Stephen Cole Kleene Born: 5 Jan 1909 in Hartford, Connecticut, USA Died: 25 Jan 1994 in Madison, Wisconsin, USA Stephen C Kleene 's father was Gustav Adolph Kleene , a professor of economics at Trinity College, Hartford, Connecticut at the time of his son's birth. He remained there for the rest of his career. He retired, becoming professor emeritus, and died at his summer home in Union, Maine in August 1946. This home was on a farm in Maine which had been Gustav's father's and both Gustav and his son Stephen considered this farm their 'real home.' Gustav wrote books such as The problem of medical charity (1904) and Profit and wages: A study in the distribution of income (1916). Stephen 's mother was Alice Lena Cole who was a poet and writer of plays. Before marrying she published poems such as The lawsuit published in The Youth's Companion (1892), The dead bee published in The Century (1899), The lost spell published in Atlantic Monthly (1900) and Escape published in Atlantic Monthly (1900). After her marriage she published KIRSTIN; KIRSTIN. Play in Four Acts (1914) under her married name Alice Cole Kleene. It was described by a critic in the New York Times as a "pretty play with graceful lyrics." Stephen Kleene studied for his first degree at Amherst College, Amherst, Massachusetts, being awarded his Bachelor's Degree summa cum laude in 1930. He then went to Princeton University where his doctoral studies were supervised by Alonso Church . It had been Oswald Veblen who had proposed that the development of logic required careful analysis by mathematicians . Church , one of Veblen 's students, had been appointed to Princeton in 1929 and was making remarkable advances in this area. J Barkley Rosser was also a doctoral student of Church 's at Princeton, arriving in 1933 while Kleene was there. It was certainly an exciting place to be undertaking research applying mathematical techniques to logic with visitors such as Kurt Gdel - Kleene attended a course he gave at the Institute for Advanced Study. Kleene received a doctorate from Princeton for his thesis entitled A Theory of Positive Integers in Formal Logic in 1934 . He writes in the Introduction to his thesis: ... we shall be concerned primarily with the development of the system of logic based on a set of postulates proposed by A Church . Our object is to demonstrate empirically that the system is adequate for the theory of positive integers, by exhibiting a construction of a significant portion of the theory within the system. By carrying out the construction on the basis of a certain subset of Church 's formal axioms, we show that this portion at least of the theory of positive integers can be deduced from logic without the use of the notions of negation, class, and description . After the award of his doctorate Kleene taught at Princeton until he joined the University of Wisconsin at Madison as an Instructor in 1935. He was promoted to Assistant Professor at Wisconsin in 1937 before leaving in 1941 (unhappy at his failure to be promoted) to become Assistant Professor back at Amherst College where he had studied for his first degree. In 1942 he married Nancy Elliot ; they had four children, Paul, Kenneth, Bruce, and Nancy . Nancy Elliot was the daughter of George Roy Elliott, professor of English at Amherst College and a literary critic who specialized in Shakespeare. Also in 1942 Kleene left Amherst College to undertake war service with the US Navy as a navigation instructor at the Naval Reserve Midshipmen's School in New York. Later he was a project director at the Naval Research Laboratory in Washington DC . By the time he left the navy after the end of World War II, Kleene had risen to the rank of lieutenant commander . He returned to the University of Wisconsin at Madison in 1946 as an associate professor being promoted to full professor two years later. In 1964 he was named Cyrus C Duffee Professor and continued to hold that chair until he retired in 1979. He served two terms as the Chair of the Department of Mathematics and one term as the Chair of the Department of Numerical Analysis (later renamed the Department of Computer Science). He also served as Dean of the College of Letters and Science in 1969-74. During his years at the University of Wisconsin he was thesis advisor to 13 Ph.D. students. In 1970 Kleene's wife Nancy died. Eight years later he remarried Jeanne Steinmetz. He died of pneumonia aged 85. Kleene's research was on the theory of algorithms and recursive function theory , an area which he created and retained an interest in throughout his life. He developed the field of recursion theory with Church , Gdel , Turing and others. He contributed to mathematical Intuitionism which had been founded by Brouwer . In particular he lectured on Recursive functions and intuitionistic mathematics at the International Congress of Mathematicians in Cambridge, Massachusetts, in 1950 . In this lecture he spoke about how his interpretation of intuitionistic number theory by means of a "realization" might extend to intuitionistic set theory . He explored these ideas further in the book The foundations of intuitionistic mathematics, especially in relation to recursive functions (1965) written jointly with Richard Vesley. Chapters I, II, and IV of the book were written by Kleene while Chapter III is by Vesley. G Kreisel writes in a review:- Chapter I is by far the best introduction to intuitionistic logic which is at present available for a mathematical logician. Michael Dummett, a leading authority, was also greatly impressed:- ... chapter one of this book provides the first systematic exposition of the foundations of intuitionist analysis set out as an axiomatic system treating Brouwer 's fan theorem, the bar theorem, and the continuity principle ( called Brouwer 's principle ) . In these respects, this was far superior to the earlier well-known axiomatization by Heyting . Kleene's work on recursion theory helped to provide the foundations of theoretical computer science . By providing methods of determining which problems are soluble, Kleene's work led to the study of which functions can be computed. He spent the summer of 1951 at the RAND Corporation and discovered an important characterisation of finite automata. His RAND report on his work that summer has been very influential for theoretical computer science. At a lecture in the University of Chicago in 1995, Robert Soare described Kleene's work in these terms:- Kleene's formulation of computable function via six schemata is one of the most succinct and useful, and his previous work on lambda functions played a major role in supporting Church 's Thesis that these classes coincide with the intuitively calculable functions . From 1930's on Kleene more than any other mathematician developed the notions of computability and effective process in all their forms both abstract and concrete, both mathematical and philosophical. He tended to lay the foundations for an area and then move on to the next, as each successive one blossomed into a major research area in his wake. Kleene developed a diverse array of topics in computability: the arithmetical hierarchy, degrees of computability, computable ordinals and hyperarithmetic theory, finite automata and regular sets with enormous consequences for computer science, computability on higher types, recursive realizability for intuitionistic arithmetic with consequences for philosphy and for program correctness in computer science. Kleene's best known books are Introduction to Metamathematics (1952) and Mathematical Logic (1967). Kleene writes in the first of these :- The aim of this book is to provide a connected introduction to the subjects of mathematical logic and recursive functions in particular, and to the newer foundational investigations in general. J R Shoenfield, reviewing the second, writes:- The growth of the undergraduate curriculum in mathematics has given rise to a number of texts treating serious mathematical results in a slower and more detailed manner than is customary in graduate texts . Since the number of such texts in the field of logic is quite small, this book by an outstanding authority in the field is especially welcome. ... The author clearly feels that a fairly thorough treatment of a few topics is preferable to a little bit of everything . ... Difficult proofs are broken down into a large number of simple cases ; some of these cases are usually left to the reader. There are many illuminating examples; the author is usually more interested in giving enough examples to illustrate the important points of the proof than in giving complete details of the proof. Clarity and simplicity are never sacrificed for elegance. Historical notes and bibliographical references are frequent, but are not allowed to overshadow the mathematics. Among the awards and honours that Kleene received for his outstanding contributions we mention the Leroy P Steele Prize which he was awarded by the American Mathematical Society in 1983:- .. for three important papers which formed the basis for later developments in generalized recursion theory and descriptive set theory "Arithmetical predicates and function quantifiers", "On the forms of the predicates in the theory of constructive ordinals ( second paper ) ", and "Hierarchies of number-theoretic predicates". Perhaps his most prestigious award was the National Medal of Science presented by President Bush at a White House East Room Ceremony on 13 November 1990:- For his leadership in the theory of recursion and effective computability and for developing it into a deep and broad field of mathematical research . Other honours included election to the National Academy of Sciences (1969), election as President of the Association for Symbolic Logic (1956-58), president of the International Union of the History and the Philosophy of Science (1961) and of the Union's Division of Logic, Methodology and Philosophy of Science (1960-62). He was editor of the Journal of Symbolic Logic for twelve years. In , Keisler describes Kleene's interests outside mathematics:- Kleene had a strong interest in nature and the environment and visited his family farm in Maine almost every summer. He discovered a variety of butterfly Beloria Todde Ammiralis Ba Kleenei. He was an avid climber and, until well into his seventies, led the biannual logic picnic at Madison ( now the Kleene Memorial Logic Picnic ) on hikes up the cliffs at Devil's Lake. Steve Kleene's knowledge of mushrooms was legendary. Mac Lane . in , recounts an experience climbing with Kleene:- In 1949 he and I, about to attend a meeting at Dartmouth of the American Mathematical Society , got together on a project to climb all the peaks in the Presidential range, and we were joined by a third climber, a vacationing bellhop. Then, as we three stood finally on top of the last peak ( Mount Madison ) , a thunderstorm struck. Kleene bounded down from the peak shouting, "Get down; it's lightning." I stepped down a bit, searched for our third companion only to find him flat on the ground, unconscious. Steve ( quicker by way of his height ) went down to the Madison Pass hut for help. When we got the injured man there we found that the lightning had singed his scalp and left a blister on his foot opposite a hobnail. We ferried him to a hospital, and I ( complete with a burned-out seat of the pants ) notified his employer at the elegant Eastern Slopes Inn. He later recovered. Steve and I continued to climb assorted mountains and Steve kept on rock climbing. Keisler also describes his personality:- Although a private man, he was a skilful and enthusiastic teller of anecdotes. He possessed a powerful voice that always made it possible for others to know without seeing him whether he was in the maths building. Article by: J J O'Connor and and E F Robertson Click on this link to see a list of the Glossary entries for this page List of References (8 books/articles) Mathematicians born in the same country Honours awarded to Stephen C Kleene (Click below for those honoured in this way) Speaker at International Congress 1958 AMS Steele Prize 1983 Cross-references in MacTutor History Topics: Word problems for groups Other Web sites Encyclopaedia Britannica Mathematical Genealogy Project from： http://www-history.mcs.st-andrews.ac.uk/Biographies/Kleene.html
Recently I have read the book that was written by Gerd Baumann.The following blog articles will be the Readnots for Mathmatica for theoretical physics. Introduction Mathematica is a computer algebra system which allows the following calculations: symbolic numeric graphical acoustic.Mathematica was developed by Stephen Wolfram in the 1980s and is nowavailable for more than 15 years on a large number of computers for different operating systems (PC, HP, SGI, SUN, NeXT, VAX, etc.).Before discussing the solution steps for several problems of theoretical physics, we will present a short overview of the organization of Mathematica. If we wish to terminate our calculations and exit the Mathematica environment,we type the termination function Quit := and the related output label is Out =. an exponent is generated by CTRL+6 on your keyboard.Multiplication of two numbers can be done in two ways. In this book, the multiplication sign is replaced by a blank: 2 5=2*5 For each Mathematica function, you will find a short description of its functionality and its purpose if you type the name of the function preceded by a question mark. For example, the description of Solve .Integration of a function is executed byIntegrate . The expansion of a function f(t) in a Taylor series around t = 0 up to third order is given by Series , {t, 0, 3}].The calculation of a finite sum follows from. The Laplace transform of the function Sin is calculated using the standard function LaplaceTransform ,t,s] Classical Mechanics Classical mechanics denotes the theory of motion of particles and particle systems under conditions in which Heisenberg's uncertainty principle has essentially no effect on the motion and,therefore, may be neglected. It is the mechanics of Galilei, Newton, Lagrange, and Hamilton and it is now extended to include the mechanics of Einstein. Atpresent, the most refined form of theoretical physics is called quantum field theory, and the theory most accurately confirmed by experiment is a special case of quantum field theory called quantum electrodynamics. According to this discipline, the interactions among electrons, positrons, and electromagnetic radiation have been computed and shown to agree with the results of experiment with an over all accuracy of 1 part in 10 9 . Unfortunately, analogous attempts to describe the interactions among mesons, hyperons, and nucleons are at present unsuccessful. This section introduces some of the mathematical tools necessary to efficiently describe mechanical systems. The basic tools discussed are coordinates, transformations, scalars, vectors, tensors, vector products, derivatives, and integral relations for scalars and vector fields. We must now establish rules whereby it is possible to multiply two matrices. Let us take a column matrix for the coordinates. The multiplication of a matrix A and a matrix B is defined only if the number of columns of A is equal to the number of rows of B. For such a case, the product A.B is given by It is evident that matrix multiplication is not commutative.(A.B is not equal to B.A) An important operation on a matrix is the transposition.The transposition of a matrix A is denoted by A T Another property of matrices is that any matrix multiplied by the identity matrix is unaffected.The problem is to find the inverse matrix such that In Mathematica, the inverse of a matrix is calculated by the function Inverse[].For orthogonal matrices, there exist a connection between the inverse matrix and the transposed matrix. This connection is This symbol was introduced by Leopold Kronecker (1823–1891). the combination of two or more numbers in an array are called vectors.Vectors consist of components specifying a direction in space. The term vector is used to indicate a quantity that has both magnitude (a scalar) and direction. A vector is often represented by an arrow or a directed line segment. The length of the arrow represents the magnitude of the vector and the arrow points in the direction of the vector. Physical quantities can be of still higher complexity than scalars and vectors. For example, the inertia of a rigid body is described by a tensor. Tensors are distinguished by their rank. The combination of n vectors in an array generates, in general, an n-rank tensor. In this scheme, scalars are tensors of rank zero and vectors are first-rank tensors. We next consider another method for the combination of two vectors, the so-called vector product or cross-product. For example, the angular momentum of a body is defined as Angular momentum = Radius arm ä Linear momentum= Distance * Linear momentum* sin( ).First, we assert that this operation ä does, in fact, produce a vector. The product considered here actually produces an axial vector, but the term vector product will be used in order to be consistent with popular usage The gradient of a scalar function is of extreme importance in physics expressing the relation between a force field and a potential field. The successive operation of the gradient operator produces This important product operator is called the Laplacian and is also written The vector which results from the volume integration of a vector function throughout a volume V is given by The integral over the surface S of the projection of a vector function onto that surface is defined to be where da is an infinitesimal element of area of the surface.we calculate the work done with a force exerted on a particle that varies along the path, . where we used the Einstein summation convention to sum over the m components. Moving Particle Motion on a Helix As a first example of kinematics, let us consider the motion of a bead with constant orbital velocity confined to a helix. This motion can be divided into two parts. Motion of a Projectile we neglect the air resistance. Furthermore, we consider only kinematics; we also demand that the projectile follows a parabolic orbit with a vertical symmetry axis and with constant horizontal velocity. The motion of the ball takes place in a three-dimensional space; thus, the velocity and the location of the ball is a certain vector with three components, respectively. The general equation of the path yHxL can be obtained be eliminating the variable t in the track representation:
For seven years, the United States has allowed its fixation on the renminbi’s exchange rate to deflect attention from far more important issues in its economic relationship with China. The upcoming Strategic and Economic Dialogue between the US and China (May 3-4 in Beijing) is an excellent opportunity to examine – and rethink – America’s priorities. Since 2005, the US Congress has repeatedly flirted with legislation aimed at defending hard-pressed American workers from the presumed threat of a cheap Chinese currency. Bipartisan support for such a measure surfaced when Senators Charles Schumer (a liberal Democrat from New York) and Lindsey Graham (a conservative Republican from South Carolina) introduced the first Chinese currency bill. The argument for legislative action is tantalizingly simple: the US merchandise trade deficit has averaged a record 4.4% of GDP since 2005, with China accounting for fully 35% of the shortfall, supposedly owing to its currency manipulation. The Chinese, insists a broad coalition of politicians, business leaders, and academic economists, must revalue or face sanctions. This reasoning resonates with the US public. Opinion polls conducted in 2011 found that fully 61% of Americans believe that China represents a serious economic threat. As such, the currency debate looms as a major issue in the upcoming US presidential campaign. “Enough is enough,” President Barack Obama replied, when queried on the renminbi in the aftermath of his last meeting with Chinese President Hu Jintao. Obama’s presumptive Republican challenger, Mitt Romney, has promised to declare China guilty of currency manipulation the day he takes office. But, however appealing this logic may be, it is wrong. First, America’s trade deficit is multilateral: the US ran deficits with 88 nations in 2010. A multilateral imbalance – especially one that it is traceable to a saving shortfall – cannot be fixed by putting pressure on a bilateral exchange rate. Indeed, America’s major threat is from within. Blaming China merely impedes the heavy lifting that must be done at home – namely, boosting saving by cutting budget deficits and encouraging households to save income rather than rely on asset bubbles. Second, the renminbi has now appreciated 31.4% against the dollar since mid-2005, well in excess of the 27.5% increase called for by the original Schumer-Graham bill. Mindful of the lessons of Japan – especially its disastrous concession on sharp yen appreciation in the Plaza Accord of 1985 – the Chinese have opted, instead, for a gradual revaluation. Recent moves toward renminbi internationalization, a more open capital account, and wider currency trading bands leave little doubt that the endgame is a market-based, fully convertible renminbi. Third, there has been significant improvement in China’s external imbalance. The International Monetary Fund estimates that China’s current-account surplus will narrow to just 2.3% of GDP in 2012, after peaking at 10.1% in 2007. American officials have long bemoaned China’s saving glut as a major source of global instability. But they should look in the mirror: America’s current-account deficit this year, at an estimated $510 billion, is likely to be 2.8 times higher than China’s surplus. Finally, China has evolved from the world’s factory to its assembly line. Research shows that no more than 20% to 30% of Chinese exports to the US reflect value added inside China. Roughly 60% of Chinese exports represent shipments of “foreign invested enterprises” – in effect, Chinese subsidiaries of global multinationals. Think Apple. Globalized production platforms distort bilateral trade data between the US and China, and have little to do with the exchange rate. Rather than vilifying China as the principal economic threat to America, the relationship should be recast as an opportunity. The largest component of US aggregate demand – the consumer – is on ice. With households focused on repairing severely damaged balance sheets, inflation-adjusted private consumption has expanded at an anemic 0.5% average annual rate over the past four years. Consumer deleveraging is likely to persist for years to come, leaving the US increasingly desperate for new sources of growth. Exports top the list of possibilities. China is now America’s third largest and most rapidly growing export market. There can be no mistaking its potential to fill some of the void left by US consumers. The key to realizing that opportunity lies in access to Chinese markets – all the more significant in light of China’s upcoming pro-consumption rebalancing. Historically, China has had an open development model, with imports running at 28% of GDP since 2002 – nearly three times Japan’s 10% import ratio during its high-growth era (1960-1989). As a result, for a given increment of domestic demand, China is far more predisposed toward foreign sourcing. As the Chinese consumer emerges, demand for a wide variety of US-made goods – ranging from new-generation information technology and biotech to automotive components and aircraft – could surge. The same is true of services. At just 43% of GDP, China’s services sector is relatively tiny. There is enormous scope for America’s global services companies to expand in China, especially in transactions-intensive distribution sectors – wholesale and retail trade, domestic transportation, and supply-chain logistics, as well as in the processing segments of finance, health care, and data warehousing. The US needs to refocus the US-China trade agenda toward expanded market access in these and other areas – pushing back against Chinese policies and government procurement practices that favor domestic production and indigenous innovation. Some progress has been made, but more is needed – for example, getting China to join the World Trade Organization’s Government Procurement Agreement. At the same time, the US should reconsider antiquated Cold War restrictions on Chinese purchases of technology-intensive items. For a growth-starved US, the opportunities of market access far outweigh the currency threat. The long-dormant Chinese consumer is about to be unleashed. This plays to one of America’s greatest strengths – its zeal to compete in new markets. Shame on the US if it squanders this extraordinary chance by digging in its heels with same timeworn approach in its imminent Economic and Strategic Dialogue with China. Stephen S. Roach, a member of the faculty at Yale University, was formerly Chairman of Morgan Stanley Asia, and is the author of The Next Asia. 原文见 http://www.chinausfocus.com/slider/americas-renminbi-fixation-2/
The Swerve: How the World Became Modern 是一本研究古罗马的书，得了两个奖。 Established in the will of newspaper publisher Joseph Pulitzer in 1904, the Pulitzer Prize is among the most prestigious honors in U.S. journalism and literature. L ast year, Stephen Greenblatt, the John Cogan University Professor of the Humanities, took home a National Book Award for nonfiction for “ The Swerve: How the World Became Modern .” Today he was recognized with another prestigious literary prize. Greenblatt’s book, which describes how an ancient Roman philosophical epic helped pave the way for modern thought, was awarded the 2012 Pulitzer Prize for general nonfiction . In its citation, the Pulitzer board described “The Swerve” as “a provocative book arguing that an obscure work of philosophy, discovered nearly 600 years ago, changed the course of history by anticipating the science and sensibilities of today.” The book tells the story of Lucretius’ “ On the Nature of Things ,” which 2,000 years ago posited a number of revolutionary ideas — that the universe functioned without the aid of gods, that religious fear was damaging to human life, and that matter was made up of very small particles in eternal motion, colliding and swerving in new directions. Once thought lost, the poem was rediscovered on a library shelf in the winter of 1417 by a Poggio Bracciolini. The copying and translation of the book fueled the Renaissance, inspiring artists such as Botticelli and thinkers such as Giordano Bruno; shaped the thought of Galileo and Freud , Darwin and Einstein ; and had a revolutionary influence on writers such as Montaigne and Shakespeare and even Thomas Jefferson . Greenblatt’s book argues that the influence of Lucretius’ work washed over modern thought like a tidal wave, anticipating not only social thought, but whole branches of modern science. “It argues that the universe consists of atoms, void, and nothing else,” Greenblatt explained earlier this year at the third in a series of book talks given by Harvard faculty and alumni as part of Wintersession programming. “The atoms are eternal and always moving. Everything comes into existence simply because of the random movement of atoms, which, given enough time, will form and reform, constantly experimenting with different configurations of matter from which will eventually emerge everything we know, and into which everything we know will collapse.” Other parts of the poem presage Darwin’s theory of evolution, and suggest that humanity is not at the center of the universe, physically or spiritually. Lucretius argued that “the universe wasn’t created for human beings,” said Greenblatt. “Humans are not unique. The Earth is not the center of the universe. There are an infinite number of worlds. The soul is a material thing, just like the body. Therefore, there’s no afterlife, and no judgment, rewards, or punishments. The moral order that we have exists simply because we need to organize societies as cooperative beings. And the highest goal in life would have to be not pain or piety but pleasure, which all creatures seek.”
转自： http://blog.renren.com/blog/244073669/473431388 作者： 吴浩Tony Stephen C. Stearns 网站： Some Modest Advice for Graduate Students http://www.yale.edu/eeb/stearns/advice.htm 另一篇文章： Designs for Learning http://www.yale.edu/eeb/stearns/designs.htm Always Prepare for the Worst. Some of the greatest catastrophes in graduate education could have been avoided by a little intelligent foresight. Be cynical. Assume that your proposed research might not work, and that one of your faculty advisers might become unsupportive - or even hostile. Plan for alternatives . Nobody cares about you. In fact, some professors care about you and some don't. Most probably do, but all are busy, which means in practice they cannot care about you because they don't have the time. You are on your own, and you had better get used to it. This has a lot of implications. Here are two important ones: 1. You had better decide early on that you are in charge of your progr am. The degree you get is yours to create. Your major professor can advise you and protect you to a certain extent from bureaucratic and financial demons, but he should not tell you what to do. That is up to you . If you need advice, ask for it: that's his job. 2. If you want to pick somebody's brains, you'll have to go to him or her, because they won't be coming to you . You Must Know Why Your Work is Important. When you first arrive, read and think widely and exhaustively for a year . Assume that everything you read is bullshit until the author manages to convince you that it isn't. If you do not understand something, don't feel bad - it's not your fault, it's the author's. He didn't write clearly en ough. If some authority figure tells you that you aren't accomplishing anything because you aren't taking courses and you aren't gathering data, tell him what you're up to. If he persists, tell him to bug off, because you know what you're doing, dammit. This is a hard stage to get through because you will feel guilty about not getting going on your own research. You will continually be asking yourself, "What am I doing here?" Be patient . This stage is critical to your personal development and to maintaining the flow of new ideas into science . Here you decide what constitutes an important problem. You must arrive at this decision independently for two reasons. First, if someone hands you a problem, you won't feel that it is yours, you won't have that possessiveness that makes you want to work on it, defend it, fight for it, and make it come out beautifully. Secondly, your PhD work will shape your future . It is your choice of a field in which to carry out a life's work . It is also important to the dynamic of science that your entry be well thought out. This is one point where you can start a whole new area of research. Remember, what sense does it make to start gathering data if you don't know - and I mean really know - why you're doing it? You must establish a firm psychological stance early in your graduate career to keep from being buffeted by the many demands that will be made on your time . If you don't watch out, the pressures of course work, teaching, language requirements and who knows what else will push you around like a large, docile molecule in Brownian motion . Here are a few things to watch out for: 1. The initiation-rite nature of the PhD and its power to convince you that your value as a person is being judged. No matter how hard you try, you won't be able to avoid this one. No one does. It stems from the open-ended nature of the thesis problem. You have to decide what a "good" thesis is. A thesis can always be made better, which gets you into an infinite regress of possible improvements. Recognize that you cannot produce a "perfect" thesis. There are going to be flaws in it, as there are in everything. Settle down to make it as good as you can within the limits of time, money, energy, encouragement and thought at your disposal. You can alleviate this problem by jumping all the explicit hurdles early in the game. Get all of your course requirements and examinations out of the way as soon as possible . Not only do you thereby clear the decks for your thesis, but you also convince yourself, by successfully jumping each hurdle, that you probably are good enough after all . 2. Nothing elicits dominant behavior like subservient behavior . Expect and demand to be treated like a colleague. The paper requirements are the explicit hurdle you will have to jump, but the implicit hurdle is attaining the status of a colleague. Act like one and you'll be treated like one. 3. Graduate school is only one of the tools that you have at hand for shaping your own development . Be prepared to quit for awhile if something better comes up. There are three good reasons to do this. First, a real opportunity could arise that is more productive and challenging than anything you could do in graduate school and that involves a long enough block of time to justify dropping out. Examples include field work in Africa on a project not directly related to your PhD work, a contract for software development, an opportunity to work as an aide in the nation's capital in the formulation of science policy, or an internship at a major newspaper or magazine as a science journalist. Secondly, only by keeping this option open can you function with true independence as a graduate student. If you perceive graduate school as your only option, you will be psychologically labile, inclined to get a bit desperate and insecure, and you will not be able to give your best. Thirdly, if things really are not working out for you, then you are only hurting yourself and denying resources to others by staying in graduate sc hool. There are a lot of interesting things to do in life besides being a scientist, and in some the job market is a lot better . If science is not turning you on, perhaps you should try something else . However, do not go off half-cocked. This is a serious decision. Be sure to talk to fellow graduate students and sympathetic faculty before making up your mind. Avoid Taking Lectures - They're Usually Inefficient. If you already have a good background in your field, then minimize the number of additional courses you take . This recommendation may seem counterintuitive, but it has a sound basis. Right now, you need to learn how to think for yourself. This requires active engagement, not passive listening and regurgitation. To learn to think, you need two things : large blocks of time , and as much one-on-one interaction as you can get with someone who thinks more clearly than you do . Courses just get in the way, and if you are well motivated, then reading and discussion is much more efficient and broadening than lectures. It is often a good idea to get together with a few colleagues, organize a seminar on a subject of interest, and invite a few faculty to take part. They'll probably be delighted. After all, it will be interesting for them, they'll love your initiative - and it will give them credit for teaching a course for which they don't have to do any work. How can you lose? These comments of course do not apply to courses that teach specific skills : e.g., electron microscopy, histological technique, scuba diving. Write a Proposal and Get It Criticized. A research proposal serves many functions. 1. By summarizing your year's thinking and reading, it ensures that you have gotten something out of it. 2. It makes it possible for you to defend your independence by providing a concrete demonstration that you used your time well. 3. It literally makes it possible for others to help you. What you have in mind is too complex to be communicated verbally - too subtle, and in too many parts. It must be put down in a well-organized, clearly and concisely written document that can be circulated to a few good minds. Only with a proposal before them can they give you constructive criticism. 4. You need practice writing. We all do . 5. Having located your problem and satisfied yourself that it is important, you will have to convince your colleagues that you are not totally demented and, in fact, deserve support . One way to organize a proposal to accomplish this goal is: a. A brief statement of what you propose, couched as a question or hypothesis. b. Why it is important scientifically, not why it is important to you personally, and how it fits into the broader scheme of ideas in your field. c. A literature review that substantiates (b). d. Describe your problem as a series of subproblems that can each be attacked in a series of small steps. Devise experiments, observations or analyses that will permit you to exclude alternatives at each stage. Line them up and start knocking them down. By transforming the big problem into a series of smaller ones, you always know what to do next, you lower the energy threshold to begin work, you identify the part that will take the longest or cause the most problems, and you have available a list of things to do when something doesn't work out. 6. Write down a list of the major problems that could arise and ruin the whole project. Then write down a list of alternatives that you will do if things actually do go wrong. 7. It is not a bad idea to design two or three projects and start them in parallel to see which one has the best practical chance of succeeding. There could be two or three model systems that all seem to have equally good chances on paper of providing appropriate tests for your ideas, but in fact practical problems may exclude some of them. It is much more efficient to discover this at the start than to design and execute two or three projects in succession after the first fail for practical reasons. 8. Pick a date for the presentation of your thesis and work backwards in constructing a schedule of how you are going to use your time. You can expect a stab of terror at this point. Don't worry - it goes on like this for awhile, then it gradually gets worse. 9. Spend two to three weeks writing the proposal after you've finished your reading, then give it to as many good critics as you can find. Hope that their comments are tough, and respond as constructively as you can . 10. Get at it. You already have the introduction to your thesis written, and you have only been here 12 to 18 months. Manage Your Advisors. Keep your advisors aware of what you are doing, but do not bother them. Be an interesting presence, not a pest. At least once a year, submit a written progress report 1-2 pages long on your own initiative. They will appreciate it and be impressed. Anticipate and work to avoid personality problems . If you do not get along with your professors, change advisors early on . Be very careful about choosing your advisors in the first place. Most important is their interest in your interests. Types of Theses. Never elaborate a baroque excrescence on top of existing but shaky ideas. Go right to the foundations and test the implicit but unexamined assumptions of an important body of work, or lay the foundations for a new research thrust. There are, of course, other types of theses: 1. The classical thesis involves the formulation of a deductive model that makes novel and surprising predictions which you then test objectively and confirm under conditions unfavorable to the hypothesis. Rarely done and highly prized. 2. A critique of the foundations of an important body of research. Again, rare and valuable and a sure winner if properly executed. 3. The purely theoretical thesis. This takes courage, especially in a department loaded with bedrock empiricists, but can be pulled off if you are genuinely good at math and logic. 4. Gather data that someone else can synthesize. This is the worst kind of thesis, but in a pinch it will get you through. To certain kinds of people lots of data, even if they don't test a hypothesis, will always be impressive. At least the results show that you worked hard, a fact with which you can blackmail your committee into giving you the doctorate. There are really as many kinds of theses as their are graduate students. The four types listed serve as limiting cases of the good, the bad, and the ugly. Doctoral work is a chance for you to try your hand at a number of different research styles and to discover which suites you best: theory, field work, or lab work . Ideally, you will balance all three and become the rare person who can translate the theory for the empiricists and the real world for the theoreticians. Start Publishing Early. Don't kid yourself. You may have gotten into this game out of your love for plants and animals, your curiosity about nature, and your drive to know the truth, but you won't be able to get a job and stay in it unless you publish . You need to publish substantial articles in internationally recognized, refereed journals. Without them, you can forget a career in science . This sounds brutal, but there are good reasons for it, and it can be a joyful challenge and fulfillment. Science is shared knowledge . Until the results are effectively communicated, they in effect do not exist . Publishing is part of the job, and until it is done, the work is not complete. You must master the skill of writing clear, concise, well-organized scientific papers . Here are some tips about getting into the publishing game. 1. Co-author a paper with someone who has more experience. Approach a professor who is working on an interesting project and offer your services in return for a junior authorship . He'll appreciate the help and will give you lots of good comments on the paper because his name will be on it. 2. Do not expect your first paper to be world-shattering. A lot of eminent people began with a minor piece of work. The amount of information reported in the average scientific paper may be less than you think. Work up to the major journals by publishing one or two short - but competent - papers in less well-recognized journals. You will quickly discover that no matter what the reputation of the journal, all editorial boards defend the quality of their product with jealous pride - and they should! 3. If it is good enough, publish your research proposal as a critical review paper. If it is publishable, you've probably chosen the right field to work in. 4. Do not write your thesis as a monograph. Write it as a series of publishable manuscripts, and submit them early enough so that at least one or two chapters of your thesis can be presented as reprints of published articles. 5. Buy and use a copy of Strunk and White's El ements of Style . Read it before you sit down to write your first paper, then read it again at least once a year for the next three or four years. Day's book, How to Write a Scientific Paper, is also excellent . 6. Get your work reviewed before you submit it to the journal by someone who has the time to criticize your writing as well as your ideas and organization. Don't Look Down on a Master's Thesis. The only reason not to do a master's is to fulfill the generally false conceit that you're too good for that sort of thing. The master's has a number of advantages. 1. It gives you a natural way of changing schools if you want to. You can use this to broaden your background . Moreover, your ideas on what constitutes an important problem will probably be changing rapidly at this stage of your development. Your knowledge of who is doing what, and where, will be expanding rapidly. If you decide to change universities, this is the best way to do it. You leave behind people satisfied with your performance and in a position to provide well-informed letters of recommendation. You arrive with most of your PhD requirements satisfied. 2. You get much-needed experience in research and writing in a context less threatening than doctoral re search. You break yourself in gradually. In research, you learn the size of a soluble problem. People who have done master's work usually have a much easier time with the PhD. 3. You get a publication. 4. What's your hurry? If you enter the job market too quickly, you won′t be well prepared. Better to go a bit more slowly, build up a substantial background, and present yourself a bit later as a person with more and broader experience. Publish Regularly, But Not Too Much. The pressure to publish has corroded the quality of journals and the quality of intellectual life . It is far better to have published a few papers of high quality that are widely read than it is to have published a long string of minor articles that are quickly forgotten. You do have to be realistic. You will need publications to get a post-doc, and you will need more to get a faculty position and then tenure. However, to the extent that you can gather your work together in substantial packages of real quality, you will be doing both yourself and your field a favor. Most people publish only a few papers that make any difference. Most papers are cited little or not at all. About 10% of the articles published receive 90% of the citations . A paper that is not cited is time and effort wasted . Go for quality, not for quantity . This will take courage and stubbornness, but you won't regret it. If you are publishing one or two carefully considered, substantial papers in good, refereed journals each year, you're doing very well - and you've taken time to do the job right. Acknowledgements Thanks to Frank Pitelka for providing an opportunity, to Ray Huey for being a co-conspirator and sounding board and for providing a number of the comments presented here, to the various unknown graduate students who kept these ideas in circulation, and to Pete Morin for suggesting that I write them up for publication. Some Useful References. Day, R.A. 1983. How to write and publish a scientific paper . 2nd ed. iSi Press, Philadephia. 181 pp. wise and witty. Smith, R.V. 1984. Graduate research - a guide for students in the sciences . iSi Press, Philadelphia. 182 pp. complete and practical. Strunk, W. Jr, and E.B. White.1979. The elements of style . 3rd Ed. Macmillan, New York. 92 pp. the paradigm of concision.
Fornew readers and those who request to be “ 好友 good friends” please read my 公告 栏 first. Stephen Chu, the Nobel Prizewinning physicist and current U.S. Secretary of Energy, gave a talk at Harvardon “ The Role of Science, Technology and Innovation in Solving the EnergyChallenge” on December 1, 2011. The audeince filled the auditorium. Harvard had to arrange FOUR extra large lecture rooms equipped with live broadcast to satisfy the demand. Hestarted his talk by reviewing the role of scientific innovation in agriculture,information technology, and transportation showing how each subject wastransformed by discoveries and key breakthrough. To those who are versed in thesubject matter, they are well known matters in the history of science viewednow with the benefit of hindsight. For example, I am familiar with electronicsand IT. But in agriculture and transportation, new facts and insights werelearned. Henry Ford was often thought ofas the father of the automobile. But the technology of internal combustionengine was actually invented in Germany. But Ford made possible the productionof a desirable object with low cost and efficiency. From this Chu invented theverb “Henry-Forded” to say that one person or country managed to take advantageof breakthrough elsewhere and made it practical. He gave the recent example onhow SunTech (China) managed to “Henry-Ford” solar cell production to make itthe leading producer of solar power in the world. Chu concluded his talk byquoting from the work of Micheal Spence, another Nobel winning economist, ontradable and non tradable labor. Example of the former category ismanufacturing labor which can be out-sourced to any country; the example of thelatter are barbers who cuts hair, school teachers, etc. who perform personalservices. Spencenoted from extensive data analysis that for the past half century the tradablejobs in the US are steadily decreasing (being out-sourced) while the nontradable jobs held steady. This implies that US is increasing her foreign debtcontinuously in exchange for outside labor to produce “invented in the US butmade in China” goods - another phrase coined by Chu and an economic fact that cannot be long sustained. No bigsurprise but real worry some according to Chu.
Stephen Jenkins (born 1956, New Zealand) is Professor of Economic and Social Policy at the London School of Economics. He was Professor of Economics at the Institute for Social and Economic Research at the University of Essex 1994-2010, and was ISER Director April 2006-August 2009. He was previously Professor of Applied Economics at the University of Wales Swansea (1991-94), Lecturer in the School of Social Sciences at the University of Bath (1983-91), Research Fellow, University of York (1979, 1981-83), Junior Lecturer in Economics, Massey University (1978). He received his D.Phil in 1983 from the University of York. He is also currently a Research Professor at the DIW-Berlin. He was Chair (President) of the Council for the International Association for Research on Income and Wealth 2006-8, and President of the European Society for Population Economics in 1998. Stephen's first published papers were about the intergenerational inheritance of income and the economics of English provincial repertory theatre, but most subsequent ones have been about inequality and poverty measurement issues and applications using British and US data. His current research focuses on income and poverty dynamics, and uses the British Household Panel Survey. Alongside this he maintains an active interest in modelling benefit spell durations and labour force transitions. Stephen's publications have appeared in a wide range of international journals and edited volumes. He recently co-edited The Distribution of Household Welfare and Household Production (CUP, 1998, joint with Arie Kapteyn and Bernard van Praag) and The Dynamics of Child Poverty in Industrialised Countries (CUP, 2001, joint with John Micklewright and Bruce Bradbury). He joined IZA as a Research Fellow in September 2000. Email | CV | Homepage IZA，艾萨克斯大学，Stephen P. Jenkins教授：“Has income mobility in Britain changed over the last two decades?” http://www.wise.xmu.edu.cn/viewNews.asp?id=2732 被阅览数：563次 发布时间:2010/12/6 17:44:17 2010年10月26日，“WISE-IZA” 2010 秋季联合讲座第二讲在经济楼D110室顺利开讲，来自艾萨克斯大学的Stephen P. Jenkins教授通过远程视频给WISE学生做了题为“Has income mobility in Britain changed over the last two decades?”的学术报告。 首先，Jenkins教授介绍了论文背景，其即将出版的著作 《 Changing Fortunes：Household income dynamics in Britain》涉及到了论文的内容。在谈及研究的动机时，他提到一是为了对英国的收入流动性有更深入的了解，二是在Jarvis 以及他本人之前研究基础上进行拓展，三是为了解决在英国收入流动性是上升还是下降，与美国相比英国的流动性格局有什么不同等一些问题。另 外，Jenkins教授还列举了收入流动性的多种解释，并指出流动性对于社会福利的影响并不确定，多种概念也意味着有多种流动性的测度方式。 接着Jenkins教授正式介绍论文内容。他先说明了本文所使用的数据以及个人收入等几个相关定义。数据来源于British Household Panel Survey（BHPS）1991-2006年的工资数据。然后，Jenkins教授从多个角度展示了研究结果。相对位置的流动性的变化，通过可视性和数 学总结两种方法可以看出在两个连续的年度流动性的趋势并不显著，个人层次的收入的平均增长也是上下波动的。 在会计年度内，并没有流动性减少长期不平等的趋势；专注于黄金年龄的男性雇员的收入时，可能会有一些流动性的下降。 在个人层面上， 每个家庭每一年的流动性变化很大 。 流动性的变化由永久性和暂时性成分两部分组成 ，这两部分的变化趋势有广泛一致性，但当样本扩展到所有家庭时一致性减弱。 通过分析，得出以下的结论 ：在英国当短暂性差异消除后，收入的变化不大，显著的永久性差异依然存在； 英国和美国的收入性格局存在差异 ，Jenkins教授对此给出了几种可能的解释。 在最后的提问环节， WISE的博士生与Jenkins教授进行了积极的互动，给Jenkins教授留下了深刻印象。这场报告在热烈的掌声中落下了帷幕。 (WISE2010级博士生 王彰龙 WISE2010级硕士生 王越娓 蔡利容 孙桃龙 可钦峰)
Stephen Hawking: 'There is no heaven; it's a fairy story' Stephen Hawking dismisses belief in God in an exclusive interview with the Guardian. Photograph: Solar Heliospheric Observatory/Discovery Channel A belief that heaven or an afterlife awaits us is a "fairy story" for people afraid of death, Stephen Hawking has said. In a dismissal that underlines his firm rejection of religious comforts, Britain's most eminent scientist said there was nothing beyond the moment when the brain flickers for the final time. Hawking, who was diagnosed with motor neurone disease at the age of 21, shares his thoughts on death, human purpose and our chance existence in an exclusive interview with the Guardian today. The incurable illness was expected to kill Hawking within a few years of its symptoms arising, an outlook that turned the young scientist to Wagner, but ultimately led him to enjoy life more, he has said, despite the cloud hanging over his future. "I have lived with the prospect of an early death for the last 49 years. I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first," he said. "I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark," he added. Hawking's latest comments go beyond those laid out in his 2010 book, The Grand Design , in which he asserted that there is no need for a creator to explain the existence of the universe. The book provoked a backlash from some religious leaders, including the chief rabbi, Lord Sacks, who accused Hawking of committing an "elementary fallacy" of logic. The 69-year-old physicist fell seriously ill after a lecture tour in the US in 2009 and was taken to Addenbrookes hospital in an episode that sparked grave concerns for his health. He has since returned to his Cambridge department as director of research. The physicist's remarks draw a stark line between the use of God as a metaphor and the belief in an omniscient creator whose hands guide the workings of the cosmos. In his bestselling 1988 book, A Brief History of Time, Hawking drew on the device so beloved of Einstein, when he described what it would mean for scientists to develop a "theory of everything" – a set of equations that described every particle and force in the entire universe. "It would be the ultimate triumph of human reason – for then we should know the mind of God," he wrote. The book sold a reported 9 million copies and propelled the physicist to instant stardom. His fame has led to guest roles in The Simpsons, Star Trek: The Next Generation and Red Dwarf. One of his greatest achievements in physics is a theory that describes how black holes emit radiation. In the interview, Hawking rejected the notion of life beyond death and emphasised the need to fulfil our potential on Earth by making good use of our lives. In answer to a question on how we should live, he said, simply: "We should seek the greatest value of our action." In answering another, he wrote of the beauty of science, such as the exquisite double helix of DNA in biology, or the fundamental equations of physics. Hawking responded to questions posed by the Guardian and a reader in advance of a lecture tomorrow at the Google Zeitgeist meeting in London, in which he will address the question: "Why are we here?" In the talk, he will argue that tiny quantum fluctuations in the very early universe became the seeds from which galaxies, stars, and ultimately human life emerged. "Science predicts that many different kinds of universe will be spontaneously created out of nothing. It is a matter of chance which we are in," he said. Hawking suggests that with modern space -based instruments, such as the European Space Agency's Planck mission, it may be possible to spot ancient fingerprints in the light left over from the earliest moments of the universe and work out how our own place in space came to be. His talk will focus on M-theory, a broad mathematical framework that encompasses string theory, which is regarded by many physicists as the best hope yet of developing a theory of everything. M-theory demands a universe with 11 dimensions, including a dimension of time and the three familiar spatial dimensions. The rest are curled up too small for us to see. Evidence in support of M-theory might also come from the Large Hadron Collider (LHC) at Cern , the European particle physics laboratory near Geneva. One possibility predicted by M-theory is supersymmetry, an idea that says fundamental particles have heavy – and as yet undiscovered – twins, with curious names such as selectrons and squarks. Confirmation of supersymmetry would be a shot in the arm for M-theory and help physicists explain how each force at work in the universe arose from one super-force at the dawn of time. Another potential discovery at the LHC, that of the elusive Higgs boson, which is thought to give mass to elementary particles, might be less welcome to Hawking, who has a long-standing bet that the long-sought entity will never be found at the laboratory. Hawking will join other speakers at the London event, including the chancellor, George Osborne, and the Nobel prize-winning economist Joseph Stiglitz.
2010年度美国国家科学奖章获得者名单公布 http://news.sciencenet.cn//htmlnews/2010/10/238863.shtm , AS Kang, RA Lerner, SJ Benkovic - Proceedings of the , 1991 - National Acad Sciences ... CARLOS F. BARBAS III*, ANGRAY S . KANG*, RICHARD A. LERNER*, AND STEPHEN J. BENKOVICt ... Torrey Pines Road, La Jolla, CA 92037; and tDepartment of Chemistry, Pennsylvania State University, University Park, PA 16802 Contributed by Stephen J. Benkovic , June 21 ... Cited by 747 - Related articles - All 10 versions Accelerated Alzheimer-type phenotype in transgenic mice carrying both mutant amyloid precursor protein and presenilin 1 transgenes , E McGowan, X Yu, S Benkovic , P Jantzen, K Wright - Nature medicine, 1998 - nature.com Genetic causes of Alzheimer's disease (AD) include mutations in the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (P52) genes 1 . The mutant APP K670N,M67M transgenic line, Tg2576, shows markedly elevated amyloid -protein (AP) levels at an early age and, ... Cited by 692 - Related articles - BL Direct - All 4 versions Generation of a large combinatorial library of the immunoglobulin repertoire in phage lambda , AS Kang, M Alting-Mees, DR Burton, SJ Benkovic , RA - Science, 1989 - sciencemag.org 66. TA Stewart, PK Pattengale, P. Leder, Cell 38, 627 (1984). 67. C. Schoenenberger et al., EMBO J. 7, 169 (1988). 68. U. Ruther, C. Garber, D. Komitowski, R. Muller, EF Wagner, Nature 325, 412 (1987); U. Ruther, D. Komitowski, FR Schubert, EF Wagner, Oncogenie 4, 861 ... Cited by 670 - Related articles - BL Direct - All 10 versions Bioorganic mechanisms TC Bruice, SJ Benkovic - 1966 - WA Benjamin Cited by 564 - Related articles - Find in ChinaCat - All 2 versions Catalytic antibodies , K Janda, AD Napper, SJ Benkovic , RA - Cold Spring Harbor , 1987 - symposium.cshlp.org ... A. TRAMONTANO,* K. JANDA,* AD NAPPER, t SJ BENKOVIC , t AND RA LERNER* ~Department of Molecular Biology, Research Institute of Scripps Clinic ... There are about 10 s primary binding specificities in the im- munologic ~1 repertoire, and each can generate, by a process ... Cited by 404 - Related articles - All 10 versions Colloidal Au-enhanced surface plasmon resonance for ultrasensitive detection of DNA hybridization , FG Salinas, SJ Benkovic , MJ Natan, CD - J. Am. Chem. , 2000 - ACS Publications ... Lin He, Michael D. Musick, Sheila R. Nicewarner, Frank G. Salinas, Stephen J. Benkovic , Michael J. Natan, and Christine D. Keating*. ... Metal deposition occurred at a pressure of 2 10 - 6 mbar at 0.2 nm/ s , monitored by an internal QCM. ... Cited by 404 - Related articles - BL Direct - All 4 versions At the crossroads of chemistry and immunology: catalytic antibodies RA Lerner, SJ Benkovic , PG Schultz - Science, 1991 - sciencemag.org ... variable amino acids. R Hirschmann, A. Smith 3rd, C. Taylor, P. Benkovic , S . Taylor, K. Yager, P. Sprengeler, and S . Benkovic (1994) Science 265, 234-237 | Abstract | PDF Expanding the scope of RNA catalysis. Prudent JR ... Cited by 428 - Related articles - All 7 versions A perspective on enzyme catalysis SJ Benkovic , S Hammes-Schiffer - Science, 2003 - sciencemag.org The seminal hypotheses proposed over the years for enzymatic catalysis are scrutinized. The historical record is explored from both biochemical and theoretical perspectives. Particular attention is given to the impact of molecular motions within the protein on the enzyme's catalytic ... Cited by 359 - Related articles - All 9 versions Linkage of recognition and replication functions by assembling combinatorial antibody Fab libraries along phage surfaces from pnas.org , CF Barbas, KD Janda, SJ Benkovic , - Proceedings of the , 1991 - National Acad Sciences ANGRAY S . KANG*, CARLOS F. BARBAS*, KIM D. JANDA*, STEPHEN J. BENKOVICt, AND RICHARD A. LERNER** *Departments of Molecular Biology and Chemistry, The Scripps Research Institute, 10666 North Torrey Pines Road, La Jolla, CA 92037; and tDepartment of ... Cited by 303 - Related articles - All 11 versions Mechanism of DNA strand transfer reactions catalyzed by HIV-1 reverse transcriptase JA Peliska, SJ Benkovic - Science, 1992 - sciencemag.org ... articles. Mechanism of DNA strand transfer reactions catalyzed by HIV-1 reverse transcriptase. JA Peliska and SJ Benkovic Department of Chemistry, Pennsylvania State University, University Park 16802. ... Y. Li and S . Carpenter (2001) J. Gen. Virol. ... Cited by 258 - Related articles - BL Direct - All 5 versions V Mizrahi, PA Benkovic , KA Johnson, SJ Benkovic - Biochemistry, 1987 - ACS Publications ... complexes. The rate is not limited by the actual polymerization but by a separate step, possibly important in ensuring fidelity Network of coupled promoting motions in enzyme catalysis from pnas.org , PT Rajagopalan, SJ Benkovic , S - Proceedings of the , 2002 - National Acad Sciences A network of coupled promoting motions in the enzyme dihydrofolate reductase is identified and characterized. The present identification is based on genomic analysis for sequence conservation, kinetic measurements of multiple mutations, and mixed quantum/classical ... Cited by 190 - Related articles - BL Direct - All 17 versions A combinatorial approach to hybrid enzymes independent of DNA homology from 128.111.114.12 M Ostermeier, JH Shim, SJ Benkovic - Nat. Biotechnol, 1999 - 128.111.114.12 ... Marc Ostermeier, Jae Hoon Shim, and Stephen J. Benkovic * ... ITCHY A IT-A18 1100 G 101203 2 (1) IT-A8 1113 114203 9 (4) IT-A5 1129 130203 3 (1) IT-A26 1136 137203 1 (1) IT-A3 1140 141203 3 (1) IT-A1 1144 145203 3 (1) IT-A12 1144 S 146203 ... Cited by 202 - Related articles - View as HTML - All 13 versions Construction and evaluation of the kinetic scheme associated with dihydrofolate reductase from Escherichia coli CA Fierke, KA Johnson, SJ Benkovic - Biochemistry, 1987 - ACS Publications ... 4b H2F 0.5 f 0.3 0.22 f 0.06 H4F 0.06 f 0.01 0.1 f 0.01b K. Taira and S . J. Benkovic . Dersonal communication. bThis DaDer. served with the inhibitor methotrexate (Williams et al., 1979; Blakley Cocco, 1985b). Second, the ... Cited by 198 - Related articles - All 6 versions R EPLISOME-M EDIATED DNA R EPLICATION from uprm.edu SJ Benkovic , AM Valentine, F - Annual Review of , 2001 - annualreviews.org ... 70: 181-208 (Volume publication date July 2001). Stephen J. Benkovic , Ann M. Valentine, and Frank Salinas. Department of Chemistry ... helicase, T7 polymerase catalyzes the polymerization of tens of thousands of nucleotides at a rate of approximately 300 nucleotides s 1 . The ... Cited by 170 - Related articles - BL Direct - All 5 versions Kinetic mechanism whereby DNA polymerase I (Klenow) replicates DNA with high fidelity RD Kuchta, P Benkovic , SJ Benkovic - Biochemistry, 1988 - ACS Publications ... Robert D. Kuchta, Patricia Benkovic , and Stephen J. Benkovic * ... The template base( s ) to be copied along with the 3'-ter- minal base( s ) of the primer/template is (are) included in the text after each DNA . bThe labels containing a letter have a mismatched primer ... Cited by 162 - Related articles - All 3 versions Production of cyclic peptides and proteins in vivo from pnas.org , M Wall, DC Wahnon, SJ Benkovic - Proceedings of the , 1999 - National Acad Sciences ... Contributed by Stephen J. Benkovic . ... An expressed fusion protein (F) folds to form an active protein ligase (1). The enzyme catalyzes an N-to- S acyl shift (2) at the targetI N junction to produce a thioester intermediate (T), which undergoes transesterification (3) with a side-chain ... Cited by 155 - Related articles - BL Direct - All 11 versions Metallo- -lactamase: structure and mechanism Z Wang, W Fast, AM Valentine, SJ Benkovic - Current Opinion in chemical , 1999 - Elsevier ... Zhigang Wang, Walter Fast, Ann M Valentine and Stephen J Benkovic E-mail The Corresponding Author. ... The S . maltophilia L1 enzyme shares the lowest sequence identity with the other known metallo--lactamases and belongs to class Bc. ... Cited by 152 - Related articles - BL Direct - All 4 versions Relating protein motion to catalysis S Hammes-Schiffer, SJ Benkovic - Biochemistry, 2006 - annualreviews.org Abstract This review examines the linkage between protein conformational motions and enzyme catalysis. The fundamental issues related to this linkage are probed in the context of two enzymes that catalyze hydride transfer, namely dihydrofolate reductase and liver alcohol ... Cited by 147 - Related articles - BL Direct - All 3 versions Mice deficient in TNF receptors are protected against dopaminergic neurotoxicity: implications for Parkinson's disease from fasebj.org K Sriram, JM Matheson, SA Benkovic , DB Miller, MI - The FASEB Journal, 2002 - FASEB ... disease Krishnan Sriram, Joanna M. Matheson, Stanley A. Benkovic , Diane B. Miller, Michael I. Luster and James P. O'Callaghan ... Key words: brain neurodegeneration neuroprotection MPTP T he neuropathological basis of Parkinson' s disease (PD) involves a progressive ... Cited by 150 - Related articles - BL Direct - All 5 versions Kinetic mechanism of DNA polymerase I (Klenow fragment): identification of a second conformational change and evaluation of the internal equilibrium constant ME Dahlberg, SJ Benkovic - Biochemistry, 1991 - ACS Publications ... and KF-DNA,+l-PPi complexes was not observed in correct incorporation 14/20-mer as described earlier (Dahlberg Benkovic , 1991). ... Cited by 142 - Related articles - BL Direct - All 3 versions Cloning of the immunological repertoire in Escherichia coli for generation of monoclonal catalytic antibodies: construction of a heavy chain variable region-specific from pnas.org , BN Hay, KD Janda, SJ Benkovic , RA - Proceedings of the , 1989 - National Acad Sciences ... (catalytic antibodies/variable gene repertoire/antigen bhding) L. SASTRY*, M. ALTING-MEESt, W. D. HUSEt, J. M. SHORTt, J. A. SORGE*t, BN HAY*, KD JANDA*, SJ BENKOVIC *t, AND R. A. LERNER* ... 36, 1-44. 2. Lerner, R. A. Benkovic , SJ (1988) BioEssays 9, 107-112. ... Cited by 136 - Related articles - All 9 versions Chemical basis for enzyme catalysis from ucsb.edu TC Bruice, SJ Benkovic - Biochemistry, 2000 - ACS Publications ... Correlative motions appear to participate in the formation of NACs in the catechol O-methyltransferase E S complex and in the rate of turnover of dihydrofolate reduction. ... 5. Cannon, WR, and Benkovic , SJ (1998) J. Biol. Chem. 273, 2625726250. ... Cited by 137 - Related articles - BL Direct - All 8 versions Human immunodeficiency virus type 1 reverse transcriptase: spatial and temporal relationship between the polymerase and RNase H activities from pnas.org , JA Peliska, SJ Benkovic - Proceedings of the , 1992 - National Acad Sciences ... Department of Chemistry, The Pennsylvania State University, 152 Davey Laboratory, University Park, PA 16802 Contributed by Stephen J. Benkovic , July 20 ... was 50 1.l; aliquots (5 Al) were removed from the reaction mixture at each time point and quenched by addition of S Al of ... Cited by 132 - Related articles - BL Direct - All 7 versions DNA Polymerase Fidelity: Kinetics, Structure, and Checkpoints CM Joyce, SJ Benkovic - Biochemistry, 2004 - ACS Publications ... S ., Sawaya, MR, and Ellenberger, T. (1999) An open and closed case for all polymerases, Structure7, R31R35. ... 17. Dahlberg, ME, and Benkovic , SJ (1991) Kinetic mechanism of DNA polymerase I (Klenow fragment): identification of a second conformational change and ev. Cited by 133 - Related articles - BL Direct - All 4 versions Induction of an antibody that catalyzes the hydrolysis of an amide bond. KD Janda, D Schloeder, SJ Benkovic , RA - Science (New York, , 1988 - ncbi.nlm.nih.gov 1. Science. 1988 Sep 2;241(4870):1188-91. Induction of an antibody that catalyzes the hydrolysis of an amide bond. Janda KD, Schloeder D, Benkovic SJ, Lerner RA. Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, CA 92037. ... Cited by 142 - Related articles - All 6 versions Creating multiple-crossover DNA libraries independent of sequence identity from pnas.org GL Moore, CD Maranas, SJ Benkovic - Proceedings of the , 2001 - National Acad Sciences We have developed, experimentally implemented, and modeled in silico a methodology named SCRATCHY that enables the combinatorial engineering of target proteins, independent of sequence identity. The approach combines two methods for recombining genes: incremental ... Cited by 124 - Related articles - BL Direct - All 21 versions Ferritin, transferrin, and iron in selected regions of the adult and aged rat brain SA Benkovic , JR Connor - The Journal of Comparative , 1993 - Wiley Online Library ... O 1993 WILEY-LISS, INC. Page 2. 98 SA BENKOVIC AND JR CONNOR al., '87). ... Scale bars = 10 pm in A, B, DF; 20 pm in C. Page 3. Page 4. 100 TABLE 1 Summary of Cellular Distribution of Ferritin, Transfernn, and Iron in the Rat Brain' SA BENKOVIC AND JR CONNOR ... Cited by 123 - Related articles - BL Direct - All 4 versions Backbone Dynamics in Dihydrofolate Reductase Complexes: Role of Loop Flexibility in the Catalytic Mechanism Osborne, J Schnell, SJ Benkovic , HJ Dyson, PE - Biochemistry, 2001 - ACS Publications ... Michael J. Osborne, Jason Schnell, Stephen J. Benkovic , H. Jane Dyson, and Peter E. Wright* . ... 1000 s - 1 ) exhibits a deuterium isotope effect of 3, an indication that no kinetically significant reorganization of the Michaelis complex is necessary in the catalytic step (3). ... Cited by 120 - Related articles - BL Direct - All 6 versions A DNA fragment with an alpha-phosphorothioate nucleotide at one end is asymmetrically blocked from digestion by exonuclease III and can be replicated in vivo from pnas.org SD Putney, SJ Benkovic , PR - Proceedings of the , 1981 - National Acad Sciences ... Abbreviations: dATP , the Sp diastereomer of 2'-deoxyadenosine 5'-O-(1-thiotriphosphate); dAMP and dNTP are corresponding a-thio analogs; kb,kilobase( s ); bp, base pair( s ). 7350 Thepublication costs ofthis article were defrayedin partbypagecharge payment. ... Cited by 113 - Related articles - All 8 versions Iron regulation in the brain: histochemical, biochemical, and molecular considerations JR Connor, SA Benkovic - Annals of neurology, 1992 - interscience.wiley.com ... only in oligodendrocytes, but also in microglial cells in both human 1211 and rat brains ( S . A. Benkovic and JR Connor, unpublished observations). Also in rat brain (investigations in human brain are in progress), ferritin and iron are found in tanycytes that line the ventricles. ... Cited by 111 - Related articles - All 4 versions Isoforms of ferritin have a specific cellular distribution in the brain Connor, KL Boeshore, SA Benkovic , - Journal of , 1994 - interscience.wiley.com ... Connor JR, Benkovic SA (1992): Iron regulation in the brain: Histo- chemical, biochemical and molecular considerations. Ann Neurol 32:S51-S61. Connor JR, Menzies SL, St. Martin S , Mufson EJ (1991): The cellular distribution of transfemn, femtin, and iron in the human hrdin. ... Cited by 95 - Related articles - BL Direct - All 5 versions Combinatorial protein engineering by incremental truncation from pnas.org , AE Nixon, JH Shim, SJ Benkovic - Proceedings of the , 1999 - National Acad Sciences ... Contributed by Stephen J. Benkovic . ... Building on classic examples of protein fragment complementation, such as ribonuclease S (1) and -galactosidase (2), researchers have used protein fragment complementation to examine theories of protein evolution (3), protein folding ( ... Cited by 105 - Related articles - BL Direct - All 18 versions Peptide synthesis catalyzed by an antibody containing a binding site for variable amino acids , AB Smith 3rd, CM Taylor, PA Benkovic , SD Taylor, KM - Science, 1994 - sciencemag.org ... Sci. Tech- nol. B 9, 1061 (1991). 7. J. S . Foster and JE Frommer, Nature 333, 542 (1988). ... Ralph Hirschmann,* Amos B. Smith 111,* Carol M. Taylor, Patricia A. Benkovic , Scott D. Taylor, Kraig M. Yager, Paul A. Sprengeler, Stephen J. Benkovic * ... Cited by 91 - Related articles - BL Direct - All 9 versions A fluorescence-based assay for monitoring helicase activity from pnas.org , LC Sowers, DP Millar, SJ Benkovic - Proceedings of the , 1994 - National Acad Sciences ... Duarte, CA 91010; and $Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037 Contributed by Stephen J. Benkovic , March 30 ... Aliquots (10 1d) of the unwinding reaction mixture were taken at 10- s intervals and added to 10 Adof quench solution. ... Cited by 96 - Related articles - BL Direct - All 10 versions Dynamics of a flexible loop in dihydrofolate reductase from Escherichia coli and its implication for catalysis CJ Falzone, PE Wright, SJ Benkovic - Biochemistry, 1994 - ACS Publications ... This exchange process was altered (either removed or made fast on the NMR time scale) by deleting three hairpin turn forming residues from the loop and filling the gap with a singleglycine from jbc.org , ME Dahlberg, SJ Benkovic , ND Grindley, CM - Journal of Biological , 1992 - ASBMB ... duplex, the 13/ 20-mer, whose preparation, purification, and quantitation have been described previously (Kuchta et al., 1987; Dahlberg and Benkovic , 1991). ... mixing were 10, 30, and 50 p ~ . The reaction was quenched with 0.1 M EDTA at time points between 0 and 5 s and the ... Cited by 102 - Related articles - All 4 versions A mass spectrometric solution to the address problem of combinatorial libraries from psu.edu CL Brummel, INW Lee, Y Zhou, SJ Benkovic , N - Science, 1994 - nxw.chem.psu.edu ... R Milberg, and S . Mullen for helpful discussions, 5 November 1993; accepted 23 February 1994 A Mass Spectrometric Solution to the Address Problem of Combinatorial Libraries Christopher L Brummel, Irene NW Lee, Ying Zhou, Stephen J. Benkovic ,* Nicholas Winograd* The ... Cited by 97 - Related articles - BL Direct - All 9 versions The nucleotide analog 2-aminopurine as a spectroscopic probe of nucleotide incorporation by the Klenow fragment of Escherichia coli polymerase I and MW Frey, LC Sowers, DP Millar, SJ Benkovic - Biochemistry, 1995 - ACS Publications ... Previous studies with Klenow fragment from ucsc.edu DD Cox, SJ Benkovic , LM Bloom, FC - Journal of the , 1988 - ACS Publications ... DD Cox,+ S . J. Benkovic ,$ LM Bloom,' FC Bradley,+ MJ Nelson,$ L. Que, Jr.,*+ and DE Wallickt Contribution from the Department of Chemistr , University of Minnesota, Minneapolis. ... (9) Wallick, DE; Bloom, L. M.; Gaffney, BJ; Benkovic , S . J. Bio- chemistry 1984, 23, 1295-1302. ... Cited by 85 - Related articles - All 3 versions Transition-state stabilization as a measure of the efficiency of antibody catalysis JD Stewart, SJ Benkovic - 1995 - nature.com ... | ChemPort |. 12. Stewart, JD, Roberts, VA, Thomas, N., Getzoff, ED Benkovic , SJ Biochemistry 33, 19912003 (1994). 13. Posner, B., Smiley, J., Lee, I. Benkovic , S . Trends biochem. Sci. 19, 145150 (1994). | Article | PubMed | ISI | ChemPort |. 14. Stewart, JD et al. Proc. natn ... Cited by 69 - Related articles - BL Direct - All 6 versions Antibody remodeling: a general solution to the design of a metal-coordination site in an antibody binding pocket from pnas.org , BL Iverson, SA Iverson, SJ Benkovic , - Proceedings of the , 1990 - National Acad Sciences ... Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, CA 92037; and tDepartment of Chemistry, Pennsylvania State University, University Park, PA 16802 Contributed by Stephen J. Benkovic , June 1, 1990 ... Cited by 80 - Related articles - All 9 versions Evidence for a Functional Role of the Dynamics of Glycine-121 of Escherichia coli Dihydrofolate Reductase Obtained from Kinetic Analysis of a Site-Directed Mutant CE Cameron, SJ Benkovic - Biochemistry, 1997 - ACS Publications ... 19 from the catalytic center of the enzyme has large-amplitude backbone motions on the nanosecond time scale [Epstein, DM, Benkovic , SJ, and ... Single-turnover experiments indicated that hydride transfer was reduced by 200-fold to a rate of 1.3 s - 1 and was the rate-limiting ... Cited by 82 - Related articles - BL Direct - All 5 versions
Stephen J Benkovic Department of Chemistry, The Pennsylvania State University, USA Head of Section: Chemical Biology Biocatalysis 部分名著与科研绩效： http://scholar.google.com/scholar?start=0q=Stephen+J+Benkovichl=enas_sdt=2000 A perspective on enzyme catalysis SJ Benkovic , S Hammes-Schiffer - Science, 2003 - sciencemag.org The seminal hypotheses proposed over the years for enzymatic catalysis are scrutinized. The historical record is explored from both biochemical and theoretical perspectives. Particular attention is given to the impact of molecular motions within the protein on the enzyme's catalytic ... Cited by 341 - Related articles - All 10 versions 科学杂志检索结果： http://www.sciencemag.org/cgi/search?session_query_ref=rbs.queryref_1279668350094COLLECTIONS=hw1JC=sciFULLTEXT=%28Stephen+AND+J+AND+Benkovic%29FULLTEXTFIELD=lemcontentTITLEABSTRACTFIELD=lemhwcomptitleabsRESOURCETYPE=HWCITABSTRACTFIELD=lemhwcompabstractTITLEFIELD=lemhwcomptitle Science Magazine Search Results Results 1 to 10 of 64 found
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