Summary
Walter Gilbert (born March 21, 1932, Boston, Mass., U.S.) is an American molecular biologist who was awarded a share (with Paul Berg and Frederick Sanger) of the Nobel Prize for Chemistry in 1980 for his development of a method for determining the sequence of nucleotide links in the chainlike molecules of nucleic acids (DNA and RNA).
Gilbert graduated from Harvard University with a degree in physics in 1953 and took a Ph.D. in mathematics from Cambridge University in 1957. He joined the Harvard faculty as a lecturer in physics in 1958 and, as his interests changed, advanced to assistant professor of physics in 1959, associate professor of biophysics in 1964, and professor of biochemistry in 1968. In 1974 he became American Cancer Society Professor of Molecular Biology at Harvard.
In the late 1960s Gilbert confirmed the theory of Jacques Monod and Franƈois Jacob that “repressor proteins” control the genes responsible for beginning and ending protein synthesis in the cell. He was able to demonstrate the existence of a repressor in the bacterium Escherichia coli that prevents a gene from manufacturing a certain enzyme except when lactose is present. In the 1970s Gilbert developed a widely used technique of using gel electrophoresis to read the nucleotide sequences of DNA segments. The same method was developed independently by Sanger.
In 1979 Gilbert, while retaining his affiliation with Harvard, joined a group of other scientists and businessmen to form Biogen, a commercial genetic-engineering research corporation. Gilbert resigned from Biogen in 1985 and, while continuing to teach at Harvard, became a chief proponent of the Human Genome Project, a government-funded effort to compile a complete map of the gene sequences in human DNA. He became emeritus at Harvard in 1987.
Gilbert founded Myriad Genetics in 1992 and served as director and vice chairman of the board. He helped to found Paratek Pharmaceuticals (1996), a company invested in combatting bacterial resistance, and Memory Pharmaceuticals (1998), which was geared toward developing cures for central nervous system disorders. Gilbert was also managing director of BioVentures Investors, where he became a partner in 2001. He served on the advisory boards of several other biotechnology companies as well.
Details
Walter Gilbert (born March 21, 1932) is an American biochemist, physicist, molecular biology pioneer, and Nobel laureate.
Education and early life
Walter Gilbert was born in Boston, Massachusetts, on March 21, 1932, into a Jewish family, the son of Emma (Cohen), a child psychologist, and Richard V. Gilbert, an economist.
When Gilbert was seven years old, the family moved to the Washington D.C. area so his father could work under Harry Hopkins on the New Deal brain trust. While living in Washington the family became friends with the family of I.F. Stone and Wally met Stone's oldest daughter, Celia, when they were both 8. They later married at age 21.
He was educated at the Sidwell Friends School, and attended Harvard University for undergraduate and graduate studies, earning a baccalaureate in chemistry and physics in 1953 and a master's degree in physics in 1954. He studied for his doctorate at the University of Cambridge, where he earned a PhD in physics supervised by the Nobel laureate Abdus Salam in 1957.
Career and research
Gilbert returned to Harvard in 1956 and was appointed assistant professor of physics in 1959. Gilbert's wife Celia worked for James Watson, leading Gilbert to become interested in molecular biology. Watson and Gilbert ran their laboratory jointly through most of the 1960s, until Watson left for Cold Spring Harbor Laboratory. In 1964 he was promoted to associate professor of biophysics and promoted again in 1968 to professor of biochemistry.
Gilbert is a co-founder of the biotech start-up companies Biogen, with Kenneth Murray, Phillip Sharp and Charles Weissman and Myriad Genetics with Dr. Mark Skolnick and Kevin Kimberlin where he was the first chairman on their respective boards of directors. Gilbert left his position at Harvard to run Biogen as CEO, but was later asked to resign by the company's board of directors. He is a member of the Board of Scientific Governors at The Scripps Research Institute. Gilbert has served as the chairman of the Harvard Society of Fellows.
In 1996, Gilbert and Stuart B. Levy founded Paratek Pharmaceuticals. Gilbert served as chairman until 2014.
Gilbert was an early proponent of sequencing the human genome. At a March 1986 meeting in Santa Fe New Mexico he proclaimed "The total human sequence is the grail of human genetics". In 1987, he proposed starting a company called Genome Corporation to sequence the genome and sell access to the information. In an opinion piece in Nature in 1991, he envisioned completion of the human genome sequence transforming biology into a field in which computer databases would be as essential as laboratory reagents.
Gilbert returned to Harvard in 1985. Gilbert was an outspoken critic of David Baltimore in the handling of the scientific fraud accusations against Thereza Imanishi-Kari. Gilbert also joined the early controversy over the cause of AIDS. In 1962, Gilbert's PhD student in physics Gerald Guralnik extended Gilbert's work on massless particles; Guralnik's work on is widely recognized as an important thread in the discovery of the Higgs Boson.
With his PhD student Benno Müller-Hill, Gilbert was the first to purify the lac repressor, just beating out Mark Ptashne for purifying the first gene regulatory protein.
Together with Allan Maxam, Gilbert developed a new DNA sequencing method, Maxam–Gilbert sequencing, using chemical methods developed by Andrei Mirzabekov. His approach to the first synthesis of insulin via recombinant DNA lost out to Genentech's approach which used genes built up from the nucleotides rather than from natural sources. Gilbert's effort was hampered by a temporary moratorium on recombinant DNA work in Cambridge, Massachusetts, forcing his group to move their work to an English biological weapons site.
Gilbert first proposed the existence of introns and exons and explained the evolution of introns in a seminal 1978 "News and Views" paper published in Nature. In 1986, Gilbert proposed the RNA world hypothesis for the origin of life, based on a concept first proposed by Carl Woese in 1967.
Awards and honors
In 1969, Gilbert was awarded Harvard's Ledlie Prize. In 1972 he was named American Cancer Society Professor of Molecular Biology. In 1979, Gilbert was awarded the Louisa Gross Horwitz Prize from Columbia University together with Frederick Sanger. That year he was also awarded the Gairdner Prize and the Albert Lasker Award for Basic Medical Research.
Gilbert was awarded the 1980 Nobel Prize in Chemistry, shared with Frederick Sanger and Paul Berg. Gilbert and Sanger were recognized for their pioneering work in devising methods for determining the sequence of nucleotides in a nucleic acid.
Gilbert has also been honored by the National Academy of Sciences (US Steel Foundation Award, 1968); Massachusetts General Hospital (Warren Triennial Prize, 1977); the New York Academy of Sciences; (Louis and Bert Freedman Foundation Award, 1977), the Académie des Sciences of France (Prix Charles-Leopold Mayer Award, 1977). Gilbert was elected a Foreign Member of the Royal Society (ForMemRS) in 1987.
In 2002, he received the Biotechnology Heritage Award, from the Biotechnology Industry Organization (BIO) and the Chemical Heritage Foundation.
Allan Maxam and Walter Gilbert's 1977 paper "A new method for sequencing DNA" was honored by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society for 2017. It was presented to the Department of Molecular & Cellular Biology, Harvard University.
Personal life
Gilbert married Celia Stone, the daughter of I. F. Stone, in 1953 and has two children. After retiring from Harvard in 2001, Gilbert has launched an artistic career to combine art and science. His art format is centered on digital photography.
Additional Information
An organism's genome is stored in the form of long rows of building blocks, known as nucleotides, which form DNA molecules. An organism's genome can be mapped by establishing the order of the nucleotides within the DNA molecule. In 1976, Allan Maxam and Walter Gilbert developed a method by which the ends of the DNA molecule could be marked using radioactive substances. After undergoing treatment with small amounts of chemicals that react with specific nucleotides, DNA fragments of varying lengths can be obtained. After undergoing what is known as electrophoresis, the nucleotide sequences in a DNA sample can be identified.
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Summary
Paul Berg (born June 30, 1926, New York, New York, U.S.—died February 15, 2023, Stanford, California) was an American biochemist whose development of recombinant DNA techniques won him a share (with Walter Gilbert and Frederick Sanger) of the Nobel Prize for Chemistry in 1980.
After graduating from Pennsylvania State College (later renamed Pennsylvania State University) in 1948 and taking a doctorate from Western Reserve University in 1952, Berg pursued further studies at the Institute of Cytophysiology in Copenhagen and at Washington University in St. Louis, where he remained as assistant professor of microbiology until 1959. From 1959 he was associated with the medical school of Stanford University, serving as chairman of the biochemistry department in 1969–74 and becoming Willson professor (1970) and director of the Beckman Center for Molecular and Genetic Medicine (1985). He retired in 2000.
In the course of studying the actions of isolated genes, Berg developed methods for splitting DNA molecules at selected sites and attaching segments of the molecule to the DNA of a virus or plasmid, which could then enter bacterial or animal cells. The foreign DNA was incorporated into the host and caused the synthesis of proteins that were not ordinarily found there. One of the earliest practical results of recombinant technology was the development of a strain of bacteria containing the gene for producing the mammalian hormone insulin.
Details
Paul Berg (June 30, 1926 – February 15, 2023) was an American biochemist and professor at Stanford University.
He was the recipient of the Nobel Prize in Chemistry in 1980, along with Walter Gilbert and Frederick Sanger. The award recognized their contributions to basic research involving nucleic acids, especially recombinant DNA.
Berg received his undergraduate education at Penn State University, where he majored in biochemistry. He received his PhD in biochemistry from Case Western Reserve University in 1952. Berg worked as a professor at Washington University School of Medicine and Stanford University School of Medicine, in addition to serving as the director of the Beckman Center for Molecular and Genetic Medicine.
In addition to the Nobel Prize, Berg was presented with the National Medal of Science in 1983 and the National Library of Medicine Medal in 1986. Berg was a member of the Board of Sponsors for the Bulletin of the Atomic Scientists.
Early life and education
Berg was born in Brooklyn, New York City, the son of a Russian Jewish immigrant couple, Sarah Brodsky, a homemaker, and Harry Berg, a clothing manufacturer. Berg graduated from Abraham Lincoln High School in 1943, received his Bachelor of Science degree in biochemistry from Penn State University in 1948 and PhD in biochemistry from Case Western Reserve University in 1952. He was a member of the Jewish fraternity, ΒΣΡ.
Research and career:
Academic posts
After completing his graduate studies, Berg spent two years (1952–1954) as a postdoctoral fellow with the American Cancer Society, working at the Institute of Cytophysiology in Copenhagen, Denmark, and the Washington University School of Medicine, and spent additional time in 1954 as a scholar in cancer research with the department of microbiology at the Washington University School of Medicine. He worked with Arthur Kornberg, while at Washington University. Berg was also tenured as a research fellow at Clare Hall, Cambridge. He was a professor at Washington University School of Medicine from 1955 until 1959. After 1959, Berg moved to Stanford University, where he taught biochemistry from 1959 until 2000 and served as director of the Beckman Center for Molecular and Genetic Medicine from 1985 until 2000.[9] In 2000 he retired from his administrative and teaching posts, continuing to be active in research.
Research interests
Berg's postgraduate studies involved the use of radioisotope tracers to study intermediary metabolism. This resulted in the understanding of how foodstuffs are converted to cellular materials, through the use of isotopic carbons or heavy nitrogen atoms. Paul Berg's doctorate paper is now known as the conversion of formic acid, formaldehyde and methanol to fully reduced states of methyl groups in methionine. He was also one of the first to demonstrate that folic acid and B12 cofactors had roles in the processes mentioned.
Berg is arguably most famous for his pioneering work involving gene splicing of recombinant DNA. Berg was the first scientist to create a molecule containing DNA from two different species by inserting DNA from another species into a molecule. This gene-splicing technique was a fundamental step in the development of modern genetic engineering. After developing the technique, Berg used it for his studies of viral chromosomes.
Berg was a professor emeritus at Stanford. As of 2000, he stopped doing active research, to focus on other interests, including involvement in public policy for biomedical issues involving recombinant DNA and embryonic stem cells and publishing a book about geneticist George Beadle.
Berg was a member of the Board of Sponsors of the Bulletin of the Atomic Scientists. He was also an organizer of the Asilomar conference on recombinant DNA in 1975. The previous year, Berg and other scientists had called for a voluntary moratorium on certain recombinant DNA research until they could evaluate the risks. That influential conference did evaluate the potential hazards and set guidelines for biotechnology research. It can be seen as an early application of the precautionary principle.
Awards and honors:
Nobel Prize
Berg was awarded one-half of the 1980 Nobel Prize in Chemistry, with the other half being shared by Walter Gilbert and Frederick Sanger. Berg was recognized for "his fundamental studies of the biochemistry of nucleic acids, with particular regard to recombinant DNA", while Sanger and Gilbert were honored for "their contributions concerning the determination of base sequences in nucleic acids."
Other awards and honors
He was elected a Fellow of the American Academy of Arts and Sciences and a member of the United States National Academy of Sciences in 1966. In 1983, Ronald Reagan presented Berg with the National Medal of Science. That same year, he was elected to the American Philosophical Society. In 1989, he received the Golden Plate Award of the American Academy of Achievement. He was elected a Foreign Member of the Royal Society (ForMemRS) in 1992. In 2005 he was awarded the Biotechnology Heritage Award by the Biotechnology Industry Organization (BIO) and the Chemical Heritage Foundation. In 2006 he received Wonderfest's Carl Sagan Prize for Science Popularization.
Death
Berg died on February 15, 2023, at the age of 96.
Additional Information:
Life
Paul Berg grew up in Brooklyn. A teacher awakened his scientific bent when she encouraged students to conduct their own research projects. Berg was studying biochemistry at Pennsylvania State University when World War II broke out. He served on a submarine before obtaining his degree in 1948. He received his doctorate at Case Western Reserve University, and after a period in Copenhagen, he worked with Arthur Kornberg in St. Louis, Missouri. Berg made his Nobel Prize-awarded discovery at Stanford University. In 1947 he married Mildred Levy, and the couple had a son, John.
Work
DNA carries organisms' genomes and also determines their vital processes. The ability to artificially manipulate DNA opens the way to creating organisms with new characteristics. In conjunction with his studies of the tumor virus SV40, in 1972, Paul Berg succeeded in inserting DNA from a bacterium into the virus' DNA. Berg thereby created the first DNA molecule made of parts from different organisms. This type of molecule became known as hybrid DNA or recombinant DNA. Among other things, Berg's method opened the way to creating bacteria that produce substances used in medicines.
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Val Logsdon Fitch (March 10, 1923 – February 5, 2015) was an American nuclear physicist who, with co-researcher James Cronin, was awarded the 1980 Nobel Prize in Physics for a 1964 experiment using the Alternating Gradient Synchrotron at Brookhaven National Laboratory that proved that certain subatomic reactions do not adhere to fundamental symmetry principles. Specifically, they proved, by examining the decay of K-mesons, that a reaction run in reverse does not retrace the path of the original reaction, which showed that the reactions of subatomic particles are not indifferent to time. Thus the phenomenon of CP violation was discovered. This demolished the faith that physicists had that natural laws were governed by symmetry.
Born on a cattle ranch near Merriman, Nebraska, Fitch was drafted into the U.S. Army during World War II, and worked on the Manhattan Project at the Los Alamos Laboratory in New Mexico. He later graduated from McGill University, and completed his PhD in physics in 1954 at Columbia University. He was a member of the faculty at Princeton University from 1954 until his retirement in 2005.
Early life
Val Logsdon Fitch was born on a cattle ranch near Merriman, Nebraska, on March 10, 1923, the youngest of three children of Fred Fitch, a cattle rancher, and his wife Frances née Logsdon, a school teacher. He had an older brother and sister. The family farm was about 4 square miles (10 sq km) in size. The ranch was small; his father specialized in raising breeding stock. Soon after his birth, his father was badly injured in a horse riding accident and could no longer work on his ranch, so the family moved to the nearby town of Gordon, Nebraska, where his father entered the insurance business. Here he attended school, graduating from Gordon High School in 1940 as valedictorian.
Manhattan Project
Fitch attended Chadron State College for three years, then transferred to Northwestern University. This was during WWII; his studies were interrupted by being drafted into the US Army in 1943. After completing basic training, he was sent to Carnegie Institute of Technology for training under the Army Specialized Training Program Under this program, some 200,000 soldiers attended colleges for intensive courses. Fitch was in the program for less than a year before the manpower requirements of the war became too great, and the Army terminated the program. Most of the soldiers in the ASTP were posted to combat units, but Fitch was one of a hundred or so ASTP soldiers who joined the Special Engineer Detachment (SED), which provided much-needed technicians to the Manhattan Project.
The Army sent Fitch to the Manhattan Project's Los Alamos Laboratory in New Mexico. By mid-1944, about a third of the technicians at Los Alamos were from the SED. There he met many of the greats of physics including Niels Bohr, James Chadwick, Enrico Fermi, Isidor Isaac Rabi, Bruno Rossi, Emilio Segrè, Edward Teller and Richard C. Tolman, in some cases attending physics courses taught by them. He worked in the group headed by Ernest Titterton, a member of the British Mission, and became well-acquainted with the techniques of experimental physics. He participated in the drop testing of mock atomic bombs that was conducted at Wendover Army Air Field and the Naval Auxiliary Air Station Salton Sea, and worked at the Trinity site, where he witnessed the Trinity nuclear test on July 16, 1945. He was discharged from the Army in 1946. He continued to work at Los Alamos as a civilian for another year to earn money. He briefly returned to Los Alamos in summer 1948.
Academic career
His wartime experiences led Fitch to decide to become a physicist. Robert Bacher, the head of the physics division at Los Alamos, offered him a graduate assistantship at Cornell University, but first he needed to complete his undergraduate degree. Rather than return to Northwestern or Carnegie Mellon, he elected to enter McGill University, which Titterton had recommended. Fitch graduated from McGill with a bachelor's degree in electrical engineering in 1948. On the advice of Jerry Kellogg, who had been a student of Rabi's at Columbia University, and was a division head at the Los Alamos, Fitch decided to pursue his doctoral studies at Columbia. Kellogg wrote him a letter of introduction to Rabi. James Rainwater became his academic supervisor. Rainwater gave him a paper by John Wheeler concerning mu-mesic atoms, atoms in which an electron is replaced by a muon. These had never been observed; they were completely theoretical and there was no evidence that they existed, but it made a good thesis topic.
Fitch designed and built an experiment to measure the gamma rays emitted from mu-mesic atoms. As it turned out, this was a good time to search for them. Columbia had recently commissioned a cyclotron at the Nevis Laboratories that could produce muons; Robert Hofstadter had developed the thallium-activated sodium iodide gamma ray detector; and wartime advances in electronics yielded advances in components such as new phototubes needed to bring it all together. Initially nothing was found, but Rainwater suggested expanding the search beyond the energy range predicted by Wheeler on the basis of the then-accepted size of the radius of the atomic nucleus as around 1.4 × {10}^{-15} m. When this was done, they found what they had been looking for, discovering in the process that the nucleus was closer to 1.2 × {10}^{-15} m. He completed his PhD in 1954, writing his thesis on "Studies of X-rays from mu-mesonic atoms".[8] The thesis was published in the Physical Review in November 1953.
In 1949, Fitch married Elise Cunningham, a secretary who worked in the laboratory at Columbia. They had two sons. Elise died in 1972, and in 1976 he married Daisy Harper Sharp, thereby acquiring two stepdaughters and a stepson. After obtaining his doctorate, Fitch's interest shifted to strange particles and K mesons. In 1954, he joined the physics faculty at Princeton University, where he spent the rest of his career. He was the Class of 1909 Professor of Physics from 1969 to 1976, the Cyrus Fogg Brackett Professor of Physics from 1976 to 1982, and the James S. McDonnell Distinguished University Professor of Physics from 1982 to 1993, when he retired and took up the position of visiting lecturer with the rank of professor for three years before entering emeritus status. He was chair of the physics department from 1976 to 1981.
Fitch conducted much of his research at the Brookhaven National Laboratory, where he became acquainted with James Cronin. The two of them played bridge at nights while they waited for the Cosmotron to become available. Cronin had built a new kind of detector, a spark chamber spectrometer, and Fitch realized that it would be perfect for experiments with K mesons (now known as kaons), which Yale University physicist Robert Adair had suggested had interesting properties worth investigating. They could decay into either matter or antimatter. Along with two colleagues, James Christenson and René Turlay, they set up their experiment on the Alternating Gradient Synchrotron at Brookhaven. They discovered an unexpected result. The decay of neutral K mesons did not respect CP symmetry. K mesons that decayed into positrons did so faster than those that decayed into electrons. The importance of this result was not immediately appreciated; but as evidence of the Big Bang accumulated, Andrei Sakharov realized in 1967 that it explained why the universe is largely made of matter and not antimatter.[10] Put simply, they had found "the answer to the physicist's 'Why do we exist?'" For this discovery, Fitch and Cronin received the 1980 Nobel Prize in Physics.
In addition to the Nobel Prize, Fitch received the Ernest Orlando Lawrence Award in 1968, the John Price Wetherill Medal in 1976 and the National Medal of Science in 1993. He was a member of the Board of Sponsors of the Bulletin of the Atomic Scientists and the JASON defense advisory group. He was elected a Fellow of the American Physical Society in 1964 and a Member of both the National Academy of Sciences and the American Academy of Arts and Sciences in 1966. In 1981, Fitch became a founding member of the World Cultural Council[20] and received the Golden Plate Award of the American Academy of Achievement. He was president of the American Physical Society from 1988 to 1989, and he served on a number of governmental science and science policy committees, including the President's Science Advisory Committee from 1970 to 1973.
Fitch is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President George W. Bush in May 2008, urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy’s Office of Science, the National Science Foundation, and the National Institute of Standards and Technology.
He died at his home in Princeton, New Jersey, at the age of 91 on February 5, 2015.
Additional Information
Val Logsdon Fitch (born March 10, 1923, Merriman, Nebraska, U.S.—died February 5, 2015, Princeton, New Jersey) was an American particle physicist who was corecipient, with James Watson Cronin, of the Nobel Prize for Physics in 1980 for experiments conducted in 1964 that disproved the long-held theory that particle interaction should be indifferent to the direction of time.
Fitch’s early interest in chemistry shifted to physics in the mid-1940s when, as a member of the U.S. Army, he was sent to Los Alamos, New Mexico, to work on the Manhattan Project. He graduated from McGill University in Montreal with a bachelor’s degree in electrical engineering in 1948 and was awarded a Ph.D. in physics by Columbia University in 1954. That year he joined the faculty of Princeton University, and he later served (1976–81) as chair of its physics department; in 1987 he was named the James S. McDonnell Distinguished University Professor of Physics.
In experiments conducted at the Brookhaven National Laboratory in 1964, Fitch and Cronin showed that the decay of subatomic particles called K mesons could violate the general conservation law for weak interactions known as CP symmetry. Those experiments in turn necessitated physicists’ abandonment of the long-held principle of time-reversal invariance. The work done by Fitch and Cronin implied that reversing the direction of time would not precisely reverse the course of certain reactions of subatomic particles. Fitch served on various government bodies, including the President’s Science Advisory Committee (1970–73) and the National Science Foundation (1980–83), and in 1993 he was awarded the National Medal of Science.
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James Watson Cronin (born September 29, 1931, Chicago, Illinois, U.S.—died August 25, 2016, St. Paul, Minnesota) was an American particle physicist, corecipient with Val Logsdon Fitch of the 1980 Nobel Prize for Physics for an experiment that implied that reversing the direction of time would not precisely reverse the course of certain reactions of subatomic particles.
Cronin graduated from Southern Methodist University at Dallas, Texas, in 1951 and received a Ph.D. from the University of Chicago in 1955. He then joined the staff of the Brookhaven National Laboratory, Upton, New York. He taught (1958–71) at Princeton University before moving to the University of Chicago; he retired as professor emeritus there in 1997. In the 1990s Cronin became involved in the Pierre Auger Project, which led to the construction early in the 21st century of an observatory in Argentina to view and study cosmic rays.
Cronin and his colleague Fitch played a role in modifying the long-held notion that the laws of symmetry and conservation are inviolable. One of these laws, the principle of time invariance (designated T), states that particle interactions should be indifferent to the direction of time. This symmetry and two others, those of charge conjugation (C) and parity conservation (P), were once thought to govern all the laws of physics. But in 1956 the physicists Chen Ning Yang and Tsung-Dao Lee suggested, correctly, that parity conservation could be violated by particle decays involving weak interactions. Physicists abandoned the view that C, P, and T are independently true for weak interactions but saved the overall concept by proposing that any P violation must be offset by an equal C violation, a concept known as CP symmetry.
In a series of experiments conducted at Brookhaven in 1964, Cronin and Fitch showed that, in rare instances, subatomic particles called K mesons violate CP symmetry during their decay. In addition to winning the Nobel Prize, Cronin was a 1999 recipient of the National Medal of Science.
Details
James Watson Cronin (September 29, 1931 – August 25, 2016) was an American particle physicist.
Cronin and co-researcher Val Logsdon Fitch were awarded the 1980 Nobel Prize in Physics for a 1964 experiment that proved that certain subatomic reactions do not adhere to fundamental symmetry principles. Specifically, they proved, by examining the decay of kaons, that a reaction run in reverse does not merely retrace the path of the original reaction, which showed that the interactions of subatomic particles are not invariant under time reversal. Thus the phenomenon of CP violation was discovered.
Cronin received the Ernest Orlando Lawrence Award in 1976 for major experimental contributions to particle physics including fundamental work on weak interactions culminating in the discovery of asymmetry under time reversal. In 1999, he was awarded the National Medal of Science.
Cronin was Professor Emeritus at the University of Chicago winning the prestigious Quantrell Award and a spokesperson emeritus for the Auger project. He was a member of the Board of Sponsors of the Bulletin of the Atomic Scientists.
Education and early life
James Cronin was born in Chicago on September 29, 1931. His father, James Farley Cronin, was a graduate student of classical languages at the University of Chicago. After his father had obtained his doctorate the family first moved to Alabama, and later in 1939 to Dallas, Texas, where his father became a professor of Latin and Greek at Southern Methodist University. After high school Cronin stayed in Dallas and obtained an undergraduate degree at SMU in physics and mathematics in 1951. He is of Irish descent, with his Irish ancestors immigrating from County Cork, Ireland.
For graduate school Cronin moved back to Illinois to attend the University of Chicago. His teachers there included Nobel Prize laureates Enrico Fermi, Maria Mayer, Murray Gell-Mann and Subrahmanyan Chandrasekhar. He wrote his thesis on experimental nuclear physics under supervision of Samuel K. Allison.
Research and career
After obtaining his doctorate in 1955, Cronin joined the group of Rodney L. Cool and Oreste Piccioni at Brookhaven National Laboratory, where the new Cosmotron particle accelerator had just been completed. There he started to study parity violation in the decay of hyperon particles. During that time he also met Val Fitch, who brought him to Princeton University in Fall 1958. After Cosmotron underwent magnet failure, Cronin and the Brookhaven group moved to Bevatron at the University of California, Berkeley during the first half of 1958. Cronin and Fitch studied the decays of neutral K mesons, in which they discovered CP violation in 1964. This discovery earned the duo the 1980 Nobel Prize in Physics.
After the discovery, Cronin spent a year in France at the Centre d'Études Nucléaires at Saclay. After returning to Princeton he continued studying the neutral CP violating decay modes of the long-lived neutral K meson. In 1971, he moved back to the University of Chicago to become a full professor. This was attractive for him because of a new 400 GeV particle accelerator being built at nearby Fermilab.
When he moved to Chicago, he began a long series of experiments on particle production at high transverse momentum. With physicist Pierre Piroue and colleagues we learned about many things. These are summarized in Physical Review D, vol 19, page 764 (1977). Following these experiments Cronin took a sabbatical at CERN in 1982–83, where he performed an experiment to measure of the lifetime of the neutral pion (Physics Letters vol 158 B page 81, 1985). He then switched to the study of cosmic rays. The first was a series of measurements looking for point sources of cosmic rays. No sources were found. A summary of the measurements was published in Physical Review D vol 55 page 1714 (1997). In 1998 he joined the faculty at the University of Utah on a half-time basis to work on ultra-high-energy cosmic ray physics and to jumpstart the Pierre Auger Observatory project. His appointment was to last five years, but he left after a year to continue gathering international support for the Observatory with Alan Watson and Murat Boratav.
Cronin is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President George W. Bush in May 2008, urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy's Office of Science, the National Science Foundation, and the National Institute of Standards and Technology.
Additional Information
For a long time, physicists assumed that various symmetries characterized nature. In a kind of “mirror world” where right and left were reversed and matter was replaced by antimatter, the same physical laws would apply, they posited. The left-right symmetry had already been proven violated when, in 1964, James Cronin and Val Fitch discovered that the matter-antimatter symmetry is violated when the neutral K-meson decays. Their experiment also proved that symmetry does not apply during time reversal: reactions going backward in time are not identical to those going forward.
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Sir Godfrey Newbold Hounsfield (28 August 1919 – 12 August 2004) was a British electrical engineer who shared the 1979 Nobel Prize for Physiology or Medicine with Allan MacLeod Cormack for his part in developing the diagnostic technique of X-ray computed tomography (CT).
His name is immortalised in the Hounsfield scale, a quantitative measure of radiodensity used in evaluating CT scans. The scale is defined in Hounsfield units (symbol HU), running from air at −1000 HU, through water at 0 HU, and up to dense cortical bone at +1000 HU and more.
Early life
Hounsfield was born in Sutton-on-Trent, Nottinghamshire, England on 28 August 1919. He was the youngest of five children (he has two brothers and two sisters). His father, Thomas Hounsfield was a farmer from Beighton, and was linked to the prominent Hounsfield and Newbold families of Hackenthorpe Hall, his mother was Blanche Dilcock. As a child he was fascinated by the electrical gadgets and machinery found all over his parents' farm. Between the ages of eleven and eighteen, he tinkered with his own electrical recording machines, launched himself off haystacks with his own home-made glider, and almost killed himself by using water-filled tar barrels and acetylene to see how high they could be waterjet propelled. He attended the Magnus Grammar School in Newark-on-Trent, but was not academic.
Military service and education
Shortly before World War II, he joined the Royal Air Force as a volunteer reservist where he learned the basics of electronics and radar. After the war, he attended Faraday House Electrical Engineering College in London, graduating with the DFH (Diploma of Faraday House). Before the advent of most university engineering departments, Faraday House was a specialist Electrical Engineering college that provided university level education that combined practical experience with theoretical study.
Career
In 1949, Hounsfield began work at EMI, Ltd. in Hayes, Middlesex, where he researched guided weapon systems and radar. Hounsfield incorrectly gave this date as 1951 when he wrote his autobiography which is available on the Nobel Prize website. The correct date is 10 October 1949 as stated in a biography of Hounsfield. At EMI, he became interested in computers and in 1958, he helped design the first commercially available all-transistor computer made in Great Britain: the EMIDEC 1100. Shortly afterwards, he began work on the CT scanner at EMI. He continued to improve CT scanning, introducing a whole-body scanner in 1975, and was senior researcher (and after his retirement in 1984, consultant) to the laboratories.
While on an outing in the country, Hounsfield came up with the idea that one could determine what was inside a box by taking X-ray readings at all angles around the object. He then set to work constructing a computer that could take input from X-rays at various angles to create an image of the object in "slices". Applying this idea to the medical field led him to propose what is now known as computed tomography. At the time, Hounsfield was not aware of the work that Cormack had done on the theoretical mathematics for such a device. Hounsfield built a prototype head scanner and tested it first on a preserved human brain, then on a fresh cow brain from a butcher’s shop, and later on himself. On 1 October 1971, CT scanning was introduced into medical practice with a successful scan on a cerebral cyst patient at Atkinson Morley Hospital in Wimbledon, London, United Kingdom. In 1975, Hounsfield built a whole-body scanner. The principles of computed tomography developed by Hounsfield remain in use today (2022).
Awards and honours
In 1979, Hounsfield and Cormack received the Nobel Prize in Physiology or Medicine.
Hounsfield received numerous awards in addition to the Nobel Prize. He was appointed Commander of the Order of the British Empire in 1976 and knighted in 1981.
In 1974, he received the Wilhelm Exner Medal. Hounsfield was elected a Fellow of the Royal Society (FRS) in 1975. In 1976, he received the Golden Plate Award of the American Academy of Achievement. He was awarded the Howard N. Potts Medal in 1977. In 1994 he was elected an Honorary Fellow of the Royal Academy of Engineering.
The Hounsfield Facility for 3-D CT imaging at the University of Nottingham, opened in 2014, was named after him. It was designed to apply CT scanning to biomaterials, especially within soil, and thus to the exploring the environment.
Personal life and death
Hounsfield enjoyed hiking and skiing. He had resolved to develop what came to be CT scanning while on a country ramble.
He retired from EMI in 1986 and used the prize money from his Nobel to build a personal laboratory in his home. Hounsfield died at Kingston upon Thames, Greater London, in 2004, at the age of 84.
Additional Information
Sir Godfrey Newbold Hounsfield, (born August 28, 1919, Newark, Nottinghamshire, England—died August 12, 2004, Kingston upon Thames), was an English electrical engineer who shared the 1979 Nobel Prize for Physiology or Medicine with Allan Cormack for his part in developing the diagnostic technique of computerized axial tomography (CAT), or computerized tomography (CT). In this technique, information obtained from X rays taken by scanners rotating around the patient are combined by a computer to yield a high-resolution image of a slice of the body.
After studying electronics and radar as a member of the Royal Air Force during World War II and at Faraday House Electrical Engineering College in London, Hounsfield joined the research staff of EMI Ltd. in 1951. He led the design team that built the first all-transistor computer in Great Britain, the EMIDEC 1100, in 1958–59. Later, while investigating the problem of pattern recognition, he developed the basic idea of CAT. Hounsfield extended the capability of a computer so that it could interpret X-ray signals so as to form a two-dimensional image of a complex object such as the human head. He pursued the application of axial tomography to medical diagnosis, building a prototype head scanner and then a body scanner at EMI. Computers soon evolved to the stage needed for processing the signals from the scanners at the same rate they were obtained, and in 1972 the first clinical test of CAT scanning was performed successfully.
For his work Hounsfield received numerous awards in addition to the Nobel Prize, and he was knighted in 1981.
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Allan MacLeod Cormack (born Feb. 23, 1924, Johannesburg, S.Af.—died May 7, 1998, Winchester, Mass., U.S.) was a South African-born American physicist who, with Godfrey Hounsfield, was awarded the 1979 Nobel Prize for Physiology or Medicine for his work in developing the powerful new diagnostic technique of computerized axial tomography (CAT). Cormack was unusual in the field of Nobel laureates because he never earned a doctorate degree in medicine or any other field of science.
After graduating from the University of Cape Town in 1944 Cormack pursued advanced studies there and at the University of Cambridge. He was a lecturer at Cape Town from 1950 to 1956 and then, after a year’s research fellowship at Harvard University, became assistant professor of physics at Tufts University. His main research at Tufts centred on the interaction of subatomic particles. He advanced to full professor in 1964, was chairman of the department from 1968 to 1976, and retired in 1980. He became a U.S. citizen in 1966.
A part-time position as physicist for a hospital radiology department first aroused Cormack’s interest in the problem of X-ray imaging of soft tissues or layers of tissue of differing densities. The two-dimensional representations of conventional X-ray plates were often unable to distinguish between such tissues. More information could be gained if X rays of the body were taken from several different directions, but conventional X-ray techniques made this procedure problematic. In the early 1960s Cormack showed how details of a flat section of soft tissues could be calculated from measurements of the attenuation of X rays passing through it from many different angles. He thus provided the mathematical technique for the CAT scan, in which an X-ray source and electronic detectors are rotated about the body and the resulting data is analyzed by a computer to produce a sharp map of the tissues within a cross section of the body. Cormack became a member of the American Academy of Arts and Sciences in 1980.
Details
Allan MacLeod Cormack (February 23, 1924 – May 7, 1998) was a South African American physicist who won the 1979 Nobel Prize in Physiology or Medicine (along with Godfrey Hounsfield) for his work on X-ray computed tomography (CT), a significant and unusual achievement since Cormack did not hold a doctoral degree in any scientific field.
Early life and education
Cormack was born on February 23, 1924, in Johannesburg, South Africa. He attended Rondebosch Boys' High School in Cape Town, where he was active in the debating and tennis teams. He received his B.Sc. in physics in 1944 from the University of Cape Town and his M.Sc. in crystallography in 1945 from the same institution. He was a doctoral student at Cambridge University from 1947 to 1949, and while at Cambridge he met his future wife, Barbara Seavey, an American physics student.
Career
After marrying Barbara, he returned to the University of Cape Town in early 1950 to lecture. Following a sabbatical at Harvard in 1956–57, the couple agreed to move to the United States, and Cormack became a professor at Tufts University in the fall of 1957. Cormack became a naturalized citizen of the United States in 1966. Although he was mainly working on particle physics, Cormack's side interest in x-ray technology led him to develop the theoretical underpinnings of CT scanning. This work was initiated at the University of Cape Town and Groote Schuur Hospital in early 1956 and continued briefly in mid-1957 after returning from his sabbatical. His results were subsequently published in two papers in the Journal of Applied Physics in 1963 and 1964. These papers generated little interest until Hounsfield and colleagues built the first CT scanner in 1971, taking Cormack's theoretical calculations into a real application. For their independent efforts, Cormack and Hounsfield shared the 1979 Nobel Prize in Physiology or Medicine. It is notable that the two built a very similar type of device without collaboration in different parts of the world. He was member of the International Academy of Science, Munich. In 1990, he was awarded the National Medal of Science.
Death
Cormack died of cancer in Winchester, Massachusetts, at age 74. He was posthumously awarded the Order of Mapungubwe on December 10, 2002, for outstanding achievements as a scientist and for co-inventing the CT scanner.
Additional Information
The discovery of X-rays and the possibility of obtaining images of the body’s interior quickly led to medical applications. The possibilities of X-ray technology were further expanded with computed tomography (CT). If X-rays are sent through the body from different angles and registered when they have passed the body, images of different cross sections are created through advanced computer calculations. Around 1957 Allan Cormack developed the necessary methods of calculation. In addition to cross sections of the body, computed tomography also provides a basis for three-dimensional images.
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Summary
Georg Wittig, (born June 16, 1897, Berlin, Ger.—died Aug. 26, 1987, Heidelberg, W.Ger.), was a German chemist whose studies of organic phosphorus compounds won him a share (with Herbert C. Brown) of the Nobel Prize for Chemistry in 1979.
Wittig graduated from the University of Marburg in 1923, received his doctorate there in 1926, and remained as a lecturer in chemistry until 1932. He taught at the Technical University in Braunschweig and at the universities of Braunschweig, Freiburg, and Tübingen before joining the faculty of the University of Heidelberg in 1956, where he became emeritus in 1965 but continued to pursue research.
In investigating reactions involving carbanions, negatively charged organic species, Wittig discovered a class of organic phosphorus compounds called ylides that mediate a particular type of reaction that became known as the Wittig reaction. This reaction proved of great value in the synthesis of complex organic compounds such as vitamins A and D2, prostaglandins, and steroids.
Details
Georg Wittig (16 June 1897 – 26 August 1987) was a German chemist who reported a method for synthesis of alkenes from aldehydes and ketones using compounds called phosphonium ylides in the Wittig reaction. He shared the Nobel Prize in Chemistry with Herbert C. Brown in 1979.
Biography
Wittig was born in Berlin, Germany and shortly after his birth moved with his family to Kassel, where his father was professor at the applied arts high school. He attended school in Kassel and started studying chemistry at the University of Tübingen 1916. He was drafted and became a lieutenant in the cavalry of Hesse-Kassel (or Hesse-Cassel). After being an Allied prisoner of war from 1918 until 1919, Wittig found it hard to restart his chemistry studies owing to overcrowding at the universities. By a direct plea to Karl von Auwers, who was professor for organic chemistry at the University of Marburg at the time, he was able to resume university study and after 3 years was awarded the Ph.D. in organic chemistry.
Karl von Auwers was able to convince him to start an academic career, leading to his habilitation in 1926. He became a close friend of Karl Ziegler, who was also doing his habilitation with Auwers during that time. The successor of Karl von Auwers, Hans Meerwein, accepted Wittig as lecturer, partly because he was impressed by the new 400-page book on stereochemistry that Wittig had written. In 1931 Wittig married Waltraud Ernst, a colleague from the Auwers working group. The invitation of Karl Fries brought him as professor to the TU Braunschweig in 1932. The time in Braunschweig became more and more problematic as the Nazis tried to get rid of Karl Fries and Wittig showed solidarity with him. After the forced retirement of Fries, in 1937 Hermann Staudinger offered Wittig a position at the University of Freiburg, partly because he knew Wittig from his book on stereochemistry in which he supported Staudinger's highly criticized theory of macromolecules. The foundations of carbanion chemistry were laid during Wittig's time in Freiburg.
In 1944 he succeeded the head of the organic chemistry department Wilhelm Schlenk at the University of Tübingen. Most of his scientific work, including the development of the Wittig reaction, was performed during this time in Tübingen. The 1956 appointment of the nearly sixty-year-old Wittig as head of the organic chemistry department at the University of Heidelberg as successor of Karl Freudenberg was exceptional even at that time. The newly built department and the close connection to the BASF convinced Wittig to take this opportunity. He worked at the University of Heidelberg even after his retirement in 1967 and published papers until 1980. Most of his awards were presented during this time at Heidelberg, such as the honorary doctorate of the Sorbonne in 1956 and the Nobel Prize in Chemistry in 1979.
Work
Wittig's contributions also include the preparation of phenyllithium and the discovery of the 1,2-Wittig rearrangement and the 2,3-Wittig rearrangement.
Wittig was well known in the chemistry community for being a consummate experimenter and observer of chemical transformations, while caring very little for the theoretical and mechanistic underpinnings of the work he produced.
Georg also has his name on a literature work titled on a compound labelled Colopidalol.
Additional Information
During chemical reactions, molecules composed of atoms meet and form new compounds. Through chemical reactions, it is possible to synthesize chemical compounds in laboratories with molecules that do not exist in nature. In 1953 Georg Wittig discovered a reaction between a phosphorous carbon compound and another carbon compound that resulted in formation of a carbon compound with a least one double bond between carbon atoms. Among other things, biologically active compounds can be formed. For example, vitamin A can be produced by artificial means with the help of this reaction.
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Summary
Herbert Charles Brown (born May 22, 1912, London, England—died December 19, 2004, Lafayette, Indiana, U.S.) was one of the leading American chemists of the 20th century. His seminal work on customized reducing agents and organoborane compounds in synthetic organic chemistry had a major impact on both academic and industrial chemical practice and led to his sharing the 1979 Nobel Prize for Chemistry with the German chemist Georg Wittig.
Early life and education
Brown was born in a Jewish settlement camp in London, a temporary way station on his parents’ migration from Ukraine to the United States, where they settled with family members living in Chicago. Brown earned a bachelor’s degree (1936) and a doctorate (1938) from the University of Chicago. His dissertation, under the direction of Hermann Schlesinger, involved the reaction of diborane with aldehydes and ketones. It was the beginning of a lifetime’s devotion to organoborane chemistry. (Boron-hydrogen compounds and their derivatives are known as borane.) Postdoctoral study of the chlorosulfonation of alkanes (hydrocarbon compounds with only single molecular bonds) may likewise be seen as the genesis of his almost equally long devotion to physical organic chemistry.
Scientific career
In 1939 Brown became Schlesinger’s personal research assistant. World War II soon came to dominate the research carried out by Schlesinger’s group at Chicago. Contributions were made to the Army Signal Corps’ desire for a convenient method for the field generation of hydrogen. Of more lasting importance, though, were the discovery and large-scale preparation of sodium borohydride and lithium aluminum hydride.
Sodium borohydride is a relatively mild reducing agent, while lithium aluminum hydride is among the most powerful. A major portion of Brown’s research at Chicago (1939–43), Wayne State University (1943–47) in Detroit, and Purdue University (1947–78) in West Lafayette, Ind., was devoted to the development of new reducing agents. As a consequence of his work, organic chemists obtained an unparalled array of reducing agents carefully tailored to specific synthetic requirements. It was this work that was alluded to in the first part of the citation for his Nobel Prize.
Incidental to this work, Brown and B.C. Subba Rao studied the reduction of ethyl oleate by sodium borohydride in the presence of aluminum chloride. While the expected reduction of the ester group did indeed take place, there was an additional uptake of active hydrogen. Rather than dismissing the anomalous result, Brown boldly speculated that the double bond in oleic acid had been “hydroborated” by the excess reagent. Further research showed that this hydroboration reaction was a general property of double bonds.
At the time of this discovery (1956), hydroboranes were virtually unknown and thought not likely to be of synthetic use. Further work by Brown and his coworkers showed that organoboranes, produced by the hydroboration reaction, were in fact capable of an extraordinary range of synthetically important reactions. This work was addressed in the second part of his Nobel Prize citation.
Brown officially retired shortly before receiving the Nobel Prize. He wrote Hydroboration (1962) and Organic Syntheses via Boranes (1975), among other works.
Details
Herbert Charles Brown (May 22, 1912 – December 19, 2004) was an American chemist and recipient of the 1979 Nobel Prize in Chemistry for his work with organoboranes.
Life and career
Brown was born Herbert Brovarnik in London, to Ukrainian Jewish immigrants from Zhitomir, Pearl (née Gorinstein) and Charles Brovarnik, a hardware store manager and carpenter. His family moved to Chicago in June 1914, when he was two years old. Brown attended Crane Junior College in Chicago, where he met Sarah Baylen, whom he would later marry. The college was under threat of closing, and Brown and Baylen transferred to Wright Junior College. In 1935 he left Wright Junior College and that autumn entered the University of Chicago, completed two years of studies in three quarters, and earned a B.S. in 1936. That same year, he became a naturalized United States citizen. On February 6, 1937, Brown married Baylen, the person he credits with making him interested in hydrides of boron, a topic related to the work in which he, together with Georg Wittig, won the Nobel prize in Chemistry in 1979. Two years after starting graduate studies, he earned a Ph.D. in 1938, also from the University of Chicago.
Unable to find a position in industry, he decided to accept a postdoctoral position. This became the beginning of his academic career. He became an instructor at the University of Chicago in 1939, and held the position for four years before moving to Wayne University in Detroit as an assistant professor. In 1946, he was promoted to associate professor. He became a professor of inorganic chemistry at Purdue University in 1947 and joined the Beta Nu chapter of Alpha Chi Sigma there in 1960. He held the position of Professor Emeritus from 1978 until his death in 2004. The Herbert C. Brown Laboratory of Chemistry was named after him on Purdue University's campus. He was an honorary member of the International Academy of Science, Munich.
During World War II, while working with Hermann Irving Schlesinger, Brown discovered a method for producing sodium borohydride (NaBH4), which can be used to produce boranes, compounds of boron and hydrogen. His work led to the discovery of the first general method for producing asymmetric pure enantiomers. The elements found as initials of his name H, C and B were his working field.
In 1969, he was awarded the National Medal of Science.
Brown was quick to credit his wife Sarah with supporting him and allowing him to focus on creative efforts by handling finances, maintaining the house and yard, etc. According to Brown, after receiving the Nobel prize in Stockholm, he carried the medal and she carried the US$100,000 award.
In 1971, he received the Golden Plate Award of the American Academy of Achievement.
He was inducted into the Alpha Chi Sigma Hall of Fame in 2000.
He died December 19, 2004, at a hospital in Lafayette, Indiana after a heart attack. His wife died May 29, 2005, aged 89.
Research
As a doctoral student at the University of Chicago, Herbert Brown studied the reactions of diborane, B2H6. Hermann Irving Schlesinger's laboratory at the University of Chicago was one of two laboratories that prepared diborane. It was a rare compound that was only prepared in small quantities. Schlesinger was researching the reactions of diborane to understand why the simplest hydrogen-boron compound is B2H6 instead of BH3.
When Brown started his own research, he observed the reactions of diborane with aldehydes, ketones, esters, and acid chlorides. He discovered that diborane reacts with aldehydes and ketones to produce dialkoxyboranes, which are hydrolyzed by water to produce alcohols. Until this point, organic chemists did not have an acceptable method of reducing carbonyls under mild conditions. Yet Brown's Ph.D. thesis published in 1939 received little interest. Diborane was too rare to be useful as a synthetic reagent.
In 1939, Brown became the research assistant in Schlesinger's laboratory. In 1940, they began to research volatile, low molecular weight uranium compounds for the National Defense Research Committee. Brown and Schlesinger successfully synthesized volatile uranium(IV) borohydride, which had a molecular weight of 298. The laboratory was asked to provide a large amount of the product for testing, but diborane was in short supply. They discovered that it could be formed by reacting lithium hydride with boron trifluoride in ethyl ether, allowing them to produce the chemical in larger quantities. This success was met with several new problems. Lithium hydride was also in short supply, so Brown and Schlesinger needed to find a procedure that would allow them to use sodium hydride instead. They discovered that sodium hydride and methyl borate reacted to produce sodium trimethoxyborohydride, which was viable as a substitute for the lithium hydride.
Soon they were informed that there was no longer a need for uranium borohydride, but it appeared that sodium borohydride could be useful in generating hydrogen. They began to look for a cheaper synthesis and discovered that adding methyl borate to sodium hydride at 250° produced sodium borohydride and sodium methoxide. When acetone was used in an attempt to separate the two products, it was discovered that sodium borohydride reduced the acetone.
Sodium borohydride is a mild reducing agent that works well in reducing aldehydes, ketones, and acid chlorides. Lithium aluminum hydride is a much more powerful reducing agent that can reduce almost any functional group. When Brown moved to Purdue University in 1947, he worked to find stronger borohydrides and milder aluminum hydrides that would provide a spectrum of reducing agents. The team of researchers at Purdue discovered that changing the metal ion of the borohydride to lithium, magnesium, or aluminum increases the reducing ability. They also found that introducing alkoxy substituents to the aluminum hydride decreases the reducing ability. They successfully developed a full spectrum of reducing agents.
While researching these reducing agents, Brown's coworker, Dr. B. C. Subba Rao, discovered an unusual reaction between sodium borohydride and ethyl oleate. The borohydride added hydrogen and boron to the carbon-carbon double bond in the ethyl oleate. The organoborane product could then be oxidized to form an alcohol. This two-step reaction is now called hydroboration-oxidation and is a reaction that converts alkenes into anti-Markovnikov alcohols. Markovnikov's rule states that, in adding hydrogen and a halide or hydroxyl group to a carbon-carbon double bond, the hydrogen is added to the less-substituted carbon of the bond and the hydroxyl or halide group is added to the more-substituted carbon of the bond. In hydroboration-oxidation, the opposite addition occurs.
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Summary
Steven Weinberg (May 3, 1933 – July 23, 2021) was an American theoretical physicist and Nobel laureate in physics for his contributions with Abdus Salam and Sheldon Glashow to the unification of the weak force and electromagnetic interaction between elementary particles.
He held the Josey Regental Chair in Science at the University of Texas at Austin, where he was a member of the Physics and Astronomy Departments. His research on elementary particles and physical cosmology was honored with numerous prizes and awards, including the 1979 Nobel Prize in physics and the 1991 National Medal of Science. In 2004, he received the Benjamin Franklin Medal of the American Philosophical Society, with a citation that said he was "considered by many to be the preeminent theoretical physicist alive in the world today." He was elected to the U.S. National Academy of Sciences, Britain's Royal Society, the American Philosophical Society, and the American Academy of Arts and Sciences.
Weinberg's articles on various subjects occasionally appeared in The New York Review of Books and other periodicals. He served as a consultant at the U.S. Arms Control and Disarmament Agency, president of the Philosophical Society of Texas, and member of the Board of Editors of Daedalus magazine, the Council of Scholars of the Library of Congress, the JASON group of defense consultants, and many other boards and committees.
Details
Steven Weinberg (born May 3, 1933, New York City, New York, U.S.—died July 23, 2021, Austin, Texas) was an American nuclear physicist who in 1979 shared the Nobel Prize for Physics with Sheldon Lee Glashow and Abdus Salam for work in formulating the electroweak theory, which explains the unity of electromagnetism with the weak nuclear force.
Weinberg and Glashow were members of the same classes at the Bronx High School of Science, New York City (1950), and Cornell University (1954). Weinberg went from Cornell to the Institute for Theoretical Physics (later known as the Niels Bohr Institute) at the University of Copenhagen for a year. He then obtained his doctorate at Princeton University in 1957.
Weinberg proposed his version of the electroweak theory in 1967. Electromagnetism and the weak force were both known to operate by the interchange of subatomic particles. Electromagnetism can operate at potentially infinite distances by means of massless particles called photons, while the weak force operates only at subatomic distances by means of massive particles called bosons. Weinberg was able to show that despite their apparent dissimilarities, photons and bosons are actually members of the same family of particles. His work, along with that of Glashow and Salam, made it possible to predict the outcome of new experiments in which elementary particles are made to impinge on one another. An important series of experiments in 1982–83 found strong evidence for the W and Z particles predicted by these scientists’ electroweak theory.
Weinberg conducted research at Columbia University and at the Lawrence Berkeley Laboratory before joining the faculty of the University of California at Berkeley (1960–69). During his last years there, he also was a Morris Loeb Lecturer (1966–67) at Harvard—a post he held on several subsequent occasions as well—and a visiting professor (1968–69) at the Massachusetts Institute of Technology; he joined the latter faculty in 1969 and moved to Harvard University in 1973 and to the University of Texas at Austin in 1983.
Additional Information
According to modern physics, four fundamental forces exist in nature. Electromagnetic interaction is one of these. The weak interaction—responsible, for example, for the beta decay of nuclei—is another. Thanks to contributions made by Steven Weinberg, Sheldon Glashow, and Abdus Salam in 1968, these two interactions were unified to one single, called electroweak. The theory predicted, for example, that weak interaction manifests itself in “neutral weak currents” when certain elementary particles interact. This was later confirmed.
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Abdus Salam (born Jan. 29, 1926, Jhang Maghiāna, Punjab, India [now in Pakistan]—died Nov. 21, 1996, Oxford, Eng.) was a Pakistani nuclear physicist who was the corecipient with Steven Weinberg and Sheldon Lee Glashow of the 1979 Nobel Prize for Physics for their work in formulating the electroweak theory, which explains the unity of the weak nuclear force and electromagnetism.
Salam attended the Government College at Lahore, and in 1952 he received his Ph.D. in theoretical physics from the University of Cambridge. He returned to Pakistan as a professor of mathematics in 1951–54 and then went back to Cambridge as a lecturer in mathematics. He became professor of theoretical physics at the Imperial College of Science and Technology, London, in 1957. Salam was the first Pakistani and the first Muslim scientist to win a Nobel Prize. In 1964 he helped found the International Centre for Theoretical Physics at Trieste, Italy, in order to provide support for physicists from Third World countries. He served as the centre’s director until his death.
Salam carried out his Nobel Prize–winning research at the Imperial College of Science and Technology in the 1960s. His hypothetical equations, which demonstrated an underlying relationship between the electromagnetic force and the weak nuclear force, postulated that the weak force must be transmitted by hitherto-undiscovered particles known as weak vector bosons, or W and Z bosons. Weinberg and Glashow reached a similar conclusion using a different line of reasoning. The existence of the W and Z bosons was eventually verified in 1983 by researchers using particle accelerators at CERN.
Details
Mohammad Abdus Salamm (29 January 1926 – 21 November 1996) was a Pakistani theoretical physicist. He shared the 1979 Nobel Prize in Physics with Sheldon Glashow and Steven Weinberg for his contribution to the electroweak unification theory. He was the first Pakistani and the first Muslim from an Islamic country to receive a Nobel Prize in science and the second from an Islamic country to receive any Nobel Prize, after Anwar Sadat of Egypt.
Salam was scientific advisor to the Ministry of Science and Technology in Pakistan from 1960 to 1974, a position from which he played a major and influential role in the development of the country's science infrastructure. Salam contributed to numerous developments in theoretical and particle physics in Pakistan. He was the founding director of the Space and Upper Atmosphere Research Commission (SUPARCO), and responsible for the establishment of the Theoretical Physics Group (TPG). For this, he is viewed as the "scientific father" of this program. In 1974, Abdus Salam departed from his country in protest after the Parliament of Pakistan passed unanimously a parliamentary bill declaring members of the Ahmadiyya Muslim community, to which Salam belonged, non-Muslim. In 1998, following the country's Chagai-I nuclear tests, the Government of Pakistan issued a commemorative stamp, as a part of "Scientists of Pakistan", to honour the services of Salam.
Salam's notable achievements include the Pati–Salam model, magnetic photon, vector meson, Grand Unified Theory, work on supersymmetry and, most importantly, electroweak theory, for which he was awarded the Nobel Prize. Salam made a major contribution in quantum field theory and in the advancement of Mathematics at Imperial College London. With his student, Riazuddin, Salam made important contributions to the modern theory on neutrinos, neutron stars and black holes, as well as the work on modernising quantum mechanics and quantum field theory. As a teacher and science promoter, Salam is remembered as a founder and scientific father of mathematical and theoretical physics in Pakistan during his term as the chief scientific advisor to the president. Salam heavily contributed to the rise of Pakistani physics within the global physics community. Up until shortly before his death, Salam continued to contribute to physics, and to advocate for the development of science in third-world countries.
Additional Information
Abdus Salam was born in Jhang, a small town in what is now Pakistan, in 1926. His father was an official in the Department of Education in a poor farming district. His family has a long tradition of piety and learning.
When he cycled home from Lahore, at the age of 14, after gaining the highest marks ever recorded for the Matriculation Examination at the University of the Punjab, the whole town turned out to welcome him. He won a scholarship to Government College, University of the Punjab, and took his MA in 1946. In the same year he was awarded a scholarship to St. John’s College, Cambridge, where he took a BA (honours) with a double First in mathematics and physics in 1949. In 1950 he received the Smith’s Prize from Cambridge University for the most outstanding pre-doctoral contribution to physics. He also obtained a PhD in theoretical physics at Cambridge; his thesis, published in 1951, contained fundamental work in quantum electrodynamics which had already gained him an international reputation.
Salam returned to Pakistan in 1951 to teach mathematics at Government College, Lahore, and in 1952 became head of the Mathematics Department of the Punjab University. He had come back with the intention of founding a school of research, but it soon became clear that this was impossible. To pursue a career of research in theoretical physics he had no alternative at that time but to leave his own country and work abroad. Many years later he succeeded in finding a way to solve the heartbreaking dilemma faced by many young and gifted theoretical physicists from developing countries. At the ICTP, Trieste, which he created, he instituted the famous “Associateships” which allowed deserving young physicists to spend their vacations there in an invigorating atmosphere, in close touch with their peers in research and with the leaders in their own field, losing their sense of isolation and returning to their own country for nine months of the academic year refreshed and recharged.
In 1954 Salam left his native country for a lectureship at Cambridge, and since then has visited Pakistan as adviser on science policy. His work for Pakistan has, however, been far-reaching and influential. He was a member of the Pakistan Atomic Energy Commission, a member of the Scientific Commission of Pakistan and was Chief Scientific Adviser to the President from 1961 to 1974.
Since 1957 he has been Professor of Theoretical Physics at Imperial College, London, and since 1964 has combined this position with that of Director of the ICTP, Trieste.
For more than forty years he has been a prolific researcher in theoretical elementary particle physics. He has either pioneered or been associated with all the important developments in this field, maintaining a constant and fertile flow of brilliant ideas. For the past thirty years he has used his academic reputation to add weight to his active and influential participation in international scientific affairs. He has served on a number of United Nations committees concerned with the advancement of science and technology in developing countries.
To accommodate the astonishing volume of activity that he undertakes, Professor Salam cuts out such inessentials as holidays, parties and entertainments. Faced with such an example, the staff of the Centre find it very difficult to complain that they are overworked.
He has a way of keeping his administrative staff at the ICTP fully alive to the real aim of the Centre – the fostering through training and research of the advancement of theoretical physics, with special regard to the needs of developing countries. Inspired by their personal regard for him and encouraged by the fact that he works harder than any of them, the staff cheerfully submit to working conditions that would be unthinkable here at the (International Atomic Energy Agency in Vienna (IAEA). The money he received from the Atoms for Peace Medal and Award he spent on setting up a fund for young Pakistani physicists to visit the ICTP. He uses his share of the Nobel Prize entirely for the benefit of physicists from developing countries and does not spend a penny of it on himself or his family.
Abdus Salam is known to be a devout Muslim, whose religion does not occupy a separate compartment of his life; it is inseparable from his work and family life. He once wrote: “The Holy Quran enjoins us to reflect on the verities of Allah’s created laws of nature; however, that our generation has been privileged to glimpse a part of His design is a bounty and a grace for which I render thanks with a humble heart.”
Abdus Salam died on November 21, 1996.
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Summary
Sheldon Glashow (born December 5, 1932, New York, New York, U.S.) is an American theoretical physicist who, with Steven Weinberg and Abdus Salam, received the Nobel Prize for Physics in 1979 for their complementary efforts in formulating the electroweak theory, which explains the unity of electromagnetism and the weak force.
Glashow was the son of Jewish immigrants from Russia. He and Weinberg were members of the same classes at the Bronx High School of Science, New York City (1950), and Cornell University (1954). Glashow received a Ph.D. in physics from Harvard University in 1958. He joined the faculty of the University of California at Berkeley in 1962 but four years later returned to Harvard as a professor of physics, Eugene Higgins Professor of Physics from 1979 onward. He remained at Harvard until 2000, when he retired as professor emeritus. That year he became Arthur G.B. Metcalf Professor of Mathematics and Science at Boston University.
In the 1960s Weinberg and Salam had each independently devised a theory by which the weak nuclear force and the electromagnetic force could be conceived as manifestations of a single unified force called the electroweak force. Their theory could be applied only to leptons, however, a class of particles that includes electrons and neutrinos. Glashow found a way to extend their theory to other classes of elementary particles, notably baryons (e.g., protons and neutrons) and mesons. In doing so, Glashow had to invent a new property for quarks, which are the fundamental particles that constitute baryons and mesons. This new property, which Glashow called “charm,” provided a valuable extension of the theory of quarks.
Details
Sheldon Lee Glashow (born December 5, 1932) is a Nobel Prize-winning American theoretical physicist. He is the Metcalf Professor of Mathematics and Physics at Boston University and Eugene Higgins Professor of Physics, emeritus, at Harvard University, and is a member of the board of sponsors for the Bulletin of the Atomic Scientists.
Birth and education
Sheldon Glashow was born on December 5, 1932, in New York City, to Jewish immigrants from Russia, Bella (née Rubin) and Lewis Gluchovsky, a plumber. He graduated from Bronx High School of Science in 1950. Glashow was in the same graduating class as Steven Weinberg, whose own research, independent of Glashow's, would result in Glashow, Weinberg, and Abdus Salam sharing the 1979 Nobel Prize in Physics. Glashow received a Bachelor of Arts degree from Cornell University in 1954 and a PhD degree in physics from Harvard University in 1959 under Nobel-laureate physicist Julian Schwinger. Afterwards, Glashow became a NSF fellow at NORDITA and met Murray Gell-Mann, who convinced him to become a research fellow at the California Institute of Technology. Glashow then became an assistant professor at Stanford University before joining the University of California, Berkeley where he was an associate professor from 1962 to 1966. He joined the Harvard physics department as a professor in 1966, and was named Eugene Higgins Professor of Physics in 1979; he became emeritus in 2000. Glashow has been a visiting scientist at CERN, and professor at Aix-Marseille University, MIT, Brookhaven Laboratory, Texas A&M, the University of Houston, and Boston University.
Research
In 1961, Glashow extended electroweak unification models due to Schwinger by including a short range neutral current, the Z0. The resulting symmetry structure that Glashow proposed, SU(2) × U(1), forms the basis of the accepted theory of the electroweak interactions. For this discovery, Glashow along with Steven Weinberg and Abdus Salam, was awarded the 1979 Nobel Prize in Physics.
In collaboration with James Bjorken, Glashow was the first to predict a fourth quark, the charm quark, in 1964. This was at a time when 4 leptons had been discovered but only 3 quarks proposed. The development of their work in 1970, the GIM mechanism showed that the two quark pairs: (d.s), (u,c), would largely cancel out flavor changing neutral currents, which had been observed experimentally at far lower levels than theoretically predicted on the basis of 3 quarks only. The prediction of the charm quark also removed a technical disaster for any quantum field theory with unequal numbers of quarks and leptons — an anomaly — where classical field theory symmetries fail to carry over into the quantum theory.
In 1973, Glashow and Howard Georgi proposed the first grand unified theory. They discovered how to fit the gauge forces in the standard model into an SU(5) group, and the quarks and leptons into two simple representations. Their theory qualitatively predicted the general pattern of coupling constant running, with plausible assumptions, it gave rough mass ratio values between third generation leptons and quarks, and it was the first indication that the law of Baryon number is inexact, that the proton is unstable. This work was the foundation for all future unifying work.
Glashow shared the 1977 J. Robert Oppenheimer Memorial Prize with Feza Gürsey.
Criticism of superstring theory
Glashow is a skeptic of superstring theory due to its lack of experimentally testable predictions. He had campaigned to keep string theorists out of the Harvard physics department, though the campaign failed. About ten minutes into "String's the Thing", the second episode of The Elegant Universe TV series, he describes superstring theory as a discipline distinct from physics, saying "...you may call it a tumor, if you will...".
Personal life
Glashow is married to Joan Shirley Alexander. They have four children. Lynn Margulis was Joan's sister, making Carl Sagan his former brother-in-law. Daniel Kleitman, who was another doctoral student of Julian Schwinger, is also his brother-in-law, through Joan's other sister, Sharon.
In 2003, he was one of 22 Nobel Laureates who signed the Humanist Manifesto. Glashow has described himself as a "practising atheist" and a Democrat.
Glashow is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President George W. Bush in May 2008, urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy’s Office of Science, the National Science Foundation, and the National Institute of Standards and Technology.
Additional Information
Born: 5 December 1932, New York, NY, USA
Affiliation at the time of the award: Harvard University, Lyman Laboratory, Cambridge, MA, USA
Prize motivation: “for their contributions to the theory of the unified weak and electromagnetic interaction between elementary particles, including, inter alia, the prediction of the weak neutral current”
Prize share: 1/3
Work
According to modern physics, four fundamental forces exist in nature. Electromagnetic interaction is one of these. The weak interaction—responsible, for example, for the beta decay of nuclei—is another. Thanks to contributions made by Sheldon Glashow, Abdus Salam, and Steven Weinberg in 1968, these two interactions were unified to one single, called electroweak. The theory predicted, for example, that weak interaction manifests itself in “neutral weak currents” when certain elementary particles interact. This was later confirmed.
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Hamilton Othanel Smith (born August 23, 1931) is an American microbiologist and Nobel laureate.
Smith graduated from University Laboratory High School of Urbana, Illinois. He attended the University of Illinois at Urbana-Champaign, but in 1950 transferred to the University of California, Berkeley, where he earned his B.A. in Mathematics in 1952 . He received his medical degree from Johns Hopkins School of Medicine in 1956. Between 1956 and 1957 Smith worked for the Washington University in St. Louis Medical Service. In 1975, he was awarded a Guggenheim Fellowship he spent at the University of Zurich.
In 1970, Smith and Kent W. Wilcox discovered the first type II restriction enzyme, which is now known as HindII. Smith went on to discover DNA methylases that constitute the other half of the bacterial host restriction and modification systems, as hypothesized by Werner Arber of Switzerland.
He was awarded the Nobel Prize in Physiology or Medicine in 1978 for discovering type II restriction enzymes with Werner Arber and Daniel Nathans as co-recipients.
He later became a leading figure in the nascent field of genomics, when in 1995 he and a team at The Institute for Genomic Research sequenced the first bacterial genome, that of Haemophilus influenzae. H. influenza was the same organism in which Smith had discovered restriction enzymes in the late 1960s. He subsequently played a key role in the sequencing of many of the early genomes at The Institute for Genomic Research, and in the assembly of the human genome at Celera Genomics, which he joined when it was founded in 1998.
More recently, he has directed a team at the J. Craig Venter Institute that works towards creating a partially synthetic bacterium, Mycoplasma laboratorium. In 2003 the same group synthetically assembled the genome of a virus, Phi X 174 bacteriophage. Smith is scientific director of privately held Synthetic Genomics, which was founded in 2005 by Craig Venter to continue this work. Synthetic Genomics is working to produce biofuels on an industrial-scale using recombinant algae and other microorganisms.
Additional Information
Hamilton O. Smith, (born August 23, 1931, New York, New York, U.S.), is an American microbiologist who shared, with Werner Arber and Daniel Nathans, the Nobel Prize for Physiology or Medicine in 1978 for his discovery of a new class of restriction enzymes that recognize specific sequences of nucleotides in a molecule of DNA (deoxyribonucleic acid) and cleave the molecule at that particular point.
Smith graduated from the University of California at Berkeley in 1952 and received a medical degree from Johns Hopkins University in 1956. After an internship and residency he joined the faculty of the University of Michigan in 1962. In 1967 he returned to Johns Hopkins, becoming professor of microbiology in 1973.
Arber and others had already studied restriction enzymes that recognize specific DNA sequences, but these type I enzymes cut the DNA at random places other than the recognition site. While studying the mechanism whereby the bacterium Haemophilus influenzae is able to take up DNA from the phage virus P22, Smith and his colleagues discovered the first of what came to be called type II restriction enzymes. These enzymes not only recognize a specific region in a DNA sequence but always cut the DNA at that very site. This predictable behaviour made type II restriction enzymes valuable tools in the study of DNA structure and in recombinant DNA technology.
In 1995, in collaboration with J. Craig Venter and researchers at The Institute for Genomics Research (TIGR), Smith sequenced the genome of H. influenzae using a rapid “shotgun” sequencing approach. In 1998 Smith left Johns Hopkins and joined the private research company Celera Genomics. At Celera Smith contributed to the genomic sequencing efforts for the fruit fly (Drosophila) and humans. In 2002 Smith became scientific director at the Institute for Biological Energy Alternatives (IBEA) in Maryland. He led research on the generation of a synthetic single-celled organism capable of surviving and reproducing on its own. A central goal of this research was to create a minimalist organism, using as few genes as possible, in order to determine how many and which genes are necessary to sustain life. In 2006 TIGR and IBEA were merged with several other centres to form the J. Craig Venter Institute, where Smith became leader of the synthetic biology and bioenergy research group.
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Daniel Nathans (October 30, 1928 – November 16, 1999) was an American microbiologist. He shared the 1978 Nobel Prize in Physiology or Medicine for the discovery of restriction enzymes and their application in restriction mapping.
Early life and education
Nathans was born in Wilmington, Delaware, the last of nine children born to Russian Jewish immigrant parents, Sarah (Levitan) and Samuel Nathans. During the Great Depression his father lost his small business and was unemployed for a long time.
Nathans attended public schools and then to the University of Delaware, where he received his BS degree in chemistry in 1950. He received his MD degree from Washington University in St. Louis in 1954 and did a one-year internship at Presbyterian Medical Center with Robert Loeb.
Wanting a break before his medical residency, Nathans became a clinical associate at the National Cancer Institute at the National Institutes of Health in Bethesda, Maryland. There he split his time between caring for patients receiving experimental cancer chemotherapy and research on recently discovered plasma-cell tumors in mice, similar to human multiple myeloma. Struck by how little was known about cancer biology, he became interested in protein synthesis in myeloma tumors, and published his first papers on this research.
Nathans returned to Columbia Presbyterian Medical Center for a two-year residency in 1957, again on Robert Loeb's service. He continued working on the problem of protein synthesis as time allowed. In 1959, he decided to work on the research full time and became a research associate at Fritz Lipmann's lab at the Rockefeller Institute in New York.
Career
In 1962, Nathans came to Johns Hopkins School of Medicine as an assistant professor of microbiology. He was promoted to associate professor in 1965 and to professor in 1967. He became the director of the microbiology department in 1972 and served in that position until 1982. In 1981, the department of microbiology was renamed the department of molecular biology and genetics.
In 1982 Johns Hopkins University made Nathans a University Professor, a position in which he served until his death in 1999. He also became a senior investigator of the Howard Hughes Medical Institute unit at Johns Hopkins School of Medicine in 1982.
From 1995 to 1996, Nathans served as the interim president of Johns Hopkins University.
In January 1999, Johns Hopkins School of Medicine established the McKusick-Nathans Institute of Genetic Medicine, a multidisciplinary clinical and research center named for Nathans and pioneering medical geneticist Victor McKusick.
Nathans was also given six honorary doctorates over the span of his career.
Additional Information
Daniel Nathans, (born Oct. 30, 1928, Wilmington, Del., U.S.—died Nov. 16, 1999, Baltimore, Md.), was an American microbiologist who was corecipient, with Hamilton Othanel Smith of the United States and Werner Arber of Switzerland, of the 1978 Nobel Prize for Physiology or Medicine. The three scientists were cited for their discovery and application of restriction enzymes that break the giant molecules of deoxyribonucleic acid (DNA) into fragments, making possible the study of the genetic information they contain. The process constitutes one of the basic tools of genetic research.
The son of Russian immigrants, Nathans attended the University of Delaware and Washington University in St. Louis, Missouri, where he earned a medical degree in 1954. He became a professor of microbiology at Johns Hopkins University in Baltimore, Maryland, in 1962 and director of its department of microbiology in 1972; he also briefly served as the school’s interim president (1995–96).
In his prizewinning research, Nathans used the restriction enzyme isolated by Smith from the bacterium Haemophilus influenzae to investigate the structure of the DNA of the simian virus 40 (SV40), the simplest virus known to produce cancerous tumours. This achievement, the construction of a genetic map of a virus, heralded the first application of restriction enzymes to the problem of identifying the molecular basis of cancer. His work also played an important role in the development of prenatal tests for such genetic diseases as cystic fibrosis and sickle cell anemia. In 1993 Nathans was awarded the National Medal of Science.
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Werner Arber (born 3 June 1929 in Gränichen, Aargau) is a Swiss microbiologist and geneticist. Along with American researchers Hamilton Smith and Daniel Nathans, Werner Arber shared the 1978 Nobel Prize in Physiology or Medicine for the discovery of restriction endonucleases. Their work would lead to the development of recombinant DNA technology.
Life and career
Arber studied chemistry and physics at the Swiss Federal Institute of Technology in Zürich from 1949 to 1953. Late in 1953, he took an assistantship for electron microscopy at the University of Geneva, in time left the electron microscope, went on to research bacteriophages and write his dissertation on defective lambda prophage mutants. In his Nobel Autobiography, he writes:
In the summer of 1956, we learned about experiments made by Larry Morse and Esther and Joshua Lederberg on the lambda-mediated transduction (gene transfer from one bacterial strain to another by a bacteriophage serving as vector) of bacterial determinants for galactose fermentation. Since these investigators had encountered defective lysogenic strains among their transductants, we felt that such strains should be included in the collection of lambda prophage mutants under study in our laboratory. Very rapidly, thanks to the stimulating help by Jean Weigle and Grete Kellenberger, this turned out to be extremely fruitful. ... This was the end of my career as an electron microscopist and in chosing [sic] genetic and physiological approaches I became a molecular geneticist.
Arber received his doctorate in 1958 from the University of Geneva. He then worked at the University of Southern California in phage genetics with Gio ("Joe") Bertani starting in the summer of 1958. Late in 1959 he accepted an offer to return to Geneva at the beginning of 1960, but only after spending "several very fruitful weeks" at each of the laboratories of Gunther Stent (University of California, Berkeley), Joshua Lederberg and Esther Lederberg (Stanford University) and Salvador Luria (Massachusetts Institute of Technology). Arber notes that it was in 1963, while he was a researcher in Stent's Berkeley lab, when experiments produced the first evidence that modification in E. coli B and K is brought about by nucleotide methylation.
Back at the University of Geneva, Arber worked in a laboratory in the basement of the Physics Institute, where he carried out productive research and hosted "a number of first class graduate students, postdoctoral fellows and senior scientists." including Daisy Roulland Dussoix, whose work helped him to later obtain the Nobel Prize. In 1965, the University of Geneva promoted him to Extraordinary Professor for Molecular Genetics. In 1971, after spending a year as a visiting Miller Professor in the Department of Molecular Biology at Berkeley, Arber moved to the University of Basel. In Basel, he was one of the first persons to work in the newly constructed Biozentrum, which housed the departments of biophysics, biochemistry, microbiology, structural biology, cell biology and pharmacology and was thus conducive to interdisciplinary research.
On 27 occasions since 1981, Werner Arber has shared his expertise and passion for science with young scientists at the Lindau Nobel Laureate Meetings.
Werner Arber is member of the World Knowledge Dialogue Scientific Board and of the Pontifical Academy of Sciences since 1981. In 1981, Arber became a founding member of the World Cultural Council. He was elected a Fellow of the American Academy of Arts and Sciences in 1984.[8] Pope Benedict XVI appointed him as President of the Pontifical Academy of Sciences in January 2011, making him the first Protestant to hold the position. In 2017, Arber retired as President of the Pontifical Academy of Sciences and was replaced by German scientist Joachim von Braun.
Personal life
Arber is married and has two daughters, including Silvia Arber.
Arber is a Christian and theistic evolutionist, stating "The most primitive cells may require at least several hundred different specific biological macromolecules. How such already quite complex structures may have come together, remains a mystery to me. The possibility of the existence of a Creator, of God, represents to me a satisfactory solution to this problem." In addition, he has affirmed: "I know that the concept of God helped me to master many questions in life; it guides me in critical situations, and I see it confirmed in many deep insights into the beauty of the functioning of the world."
Additional Information
Werner Arber, (born June 3, 1929, Gränichen, Switzerland), is a Swiss microbiologist, corecipient with Daniel Nathans and Hamilton Othanel Smith of the United States of the Nobel Prize for Physiology or Medicine for 1978. All three were cited for their work in molecular genetics, specifically the discovery and application of enzymes that break the giant molecules of deoxyribonucleic acid (DNA) into manageable pieces, small enough to be separated for individual study but large enough to retain bits of the genetic information inherent in the sequence of units that make up the original substance.
Arber studied at the Swiss Federal Institute of Technology in Zürich, the University of Geneva, and the University of Southern California. He served on the faculty at Geneva from 1960 to 1970 and later was professor of microbiology at the University of Basel (1971–96). In 2010 Pope Benedict XVI named Arber president of the Pontifical Academy of Sciences; he held the post until 2017.
During the late 1950s and early ’60s Arber and several others extended the work of an earlier Nobel laureate, Salvador Luria, who had observed that bacteriophages (viruses that infect bacteria) not only induce hereditary mutations in their bacterial hosts but at the same time undergo hereditary mutations themselves. Arber’s research was concentrated on the action of protective enzymes present in the bacteria, which modify the DNA of the infecting virus—e.g., the restriction enzyme, so-called for its ability to restrict the growth of the bacteriophage by cutting the molecule of its DNA to pieces.
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Peter Dennis Mitchell, (born Sept. 29, 1920, Mitcham, Surrey, Eng.—died April 10, 1992, Bodmin, Cornwall), is a British chemist who won the 1978 Nobel Prize for Chemistry for helping to clarify how ADP (adenosine diphosphate) is converted into the energy-carrying compound ATP (adenosine triphosphate) in the mitochondria of living cells.
Mitchell received his Ph.D. from the University of Cambridge in 1950. He served as director of the chemistry and biology unit in the department of zoology of the University of Edinburgh from 1955 to 1963. In 1964 he joined the Glynn Research Laboratories as director of research.
Mitchell studied the mitochondrion, the organelle that produces energy for the cell. ATP is made within the mitochondrion by adding a phosphate group to ADP in a process known as oxidative phosphorylation. Mitchell was able to determine how the different enzymes involved in the conversion of ADP to ATP are distributed within the membranes that partition the interior of the mitochondrion. He showed how these enzymes’ arrangement facilitates their use of hydrogen ions as an energy source in the conversion of ADP to ATP.
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Peter Dennis Mitchell (29 September 1920 – 10 April 1992) was a British biochemist who was awarded the 1978 Nobel Prize for Chemistry for his theory of the chemiosmotic mechanism of ATP synthesis.
Education and early life
Mitchell was born in Mitcham, Surrey on 29 September 1920. His parents were Christopher Gibbs Mitchell, a civil servant, and Kate Beatrice Dorothy (née) Taplin. His uncle was Sir Godfrey Way Mitchell, chairman of George Wimpey. He was educated at Queen's College, Taunton and Jesus College, Cambridge where he studied the Natural Sciences Tripos specialising in Biochemistry.
He was appointed a research post in the Department of Biochemistry, Cambridge, in 1942, and was awarded a Ph.D. in early 1951 for work on the mode of action of penicillin.
Career and research
In 1955 he was invited by Professor Michael Swann to set up a biochemical research unit, called the Chemical Biology Unit, in the Department of Zoology, at the University of Edinburgh, where he was appointed a Senior Lecturer in 1961, then Reader in 1962, although institutional opposition to his work coupled with ill health led to his resignation in 1963.
From 1963 to 1965, he supervised the restoration of a Regency-fronted Mansion, known as Glynn House, at Cardinham near Bodmin, Cornwall - adapting a major part of it for use as a research laboratory. He and his former research colleague, Jennifer Moyle founded a charitable company, known as Glynn Research Ltd., to promote fundamental biological research at Glynn House and they embarked on a programme of research on chemiosmotic reactions and reaction systems.
Chemiosmotic hypothesis
In the 1960s, ATP was known to be the energy currency of life, but the mechanism by which ATP was created in the mitochondria was assumed to be by substrate-level phosphorylation. Mitchell's chemiosmotic hypothesis was the basis for understanding the actual process of oxidative phosphorylation. At the time, the biochemical mechanism of ATP synthesis by oxidative phosphorylation was unknown.
Mitchell realised that the movement of ions across an electrochemical potential difference could provide the energy needed to produce ATP. His hypothesis was derived from information that was well known in the 1960s. He knew that living cells had a membrane potential; interior negative to the environment. The movement of charged ions across a membrane is thus affected by the electrical forces (the attraction of positive to negative charges). Their movement is also affected by thermodynamic forces, the tendency of substances to diffuse from regions of higher concentration. He went on to show that ATP synthesis was coupled to this electrochemical gradient.
His hypothesis was confirmed by the discovery of ATP synthase, a membrane-bound protein that uses the potential energy of the electrochemical gradient to make ATP; and by the discovery by André Jagendorf that a pH difference across the thylakoid membrane in the chloroplast results in ATP synthesis.
Protonmotive Q-cycle
Later, Peter Mitchell also hypothesized some of the complex details of electron transport chains. He conceived of the coupling of proton pumping to quinone-based electron bifurcation, which contributes to the proton motive force and thus, ATP synthesis.
Awards and honours
In 1978 he was awarded the Nobel Prize in Chemistry "for his contribution to the understanding of biological energy transfer through the formulation of the chemiosmotic theory." He was elected a Fellow of the Royal Society (FRS) in 1974.
Additional Information
Peter Mitchell was born in Mitcham, in the County of Surrey, England, on September 29, 1920. His parents, Christopher Gibbs Mitchell and Kate Beatrice Dorothy (née) Taplin, were very different from each other temperamentally. His mother was a shy and gentle person of very independent thought and action, with strong artistic perceptiveness. Being a rationalist and an atheist, she taught him that he must accept responsibility for his own destiny, and especially for his failings in life. That early influence may well have led him to adopt the religious atheistic personal philosophy to which he has adhered since the age of about fifteen. His father was a much more conventional person than his mother, and was awarded the O.B.E. for his success as a Civil Servant.
Peter Mitchell was educated at Queens College, Taunton, and at Jesus college, Cambridge. At Queens he benefited particularly from the influence of the Headmaster, C.L. Wiseman, who was an excellent mathematics teacher and an accomplished amateur musician. The result of the scholarship examination that he took to enter Jesus College Cambridge was so dismally bad that he was only admitted to the University at all on the strength of a personal letter written by C.L. Wiseman. He entered Jesus College just after the commencement of war with Germany in 1939. In Part I of the Natural Sciences Tripos he studied physics, chemistry, physiology, mathematics and biochemistry, and obtained a Class III result. In part II, he studied biochemistry, and obtained a II-I result for his Honours Degree.
He accepted a research post in the Department of Biochemistry, Cambridge, in 1942 at the invitation of J.F. Danielli. He was very fortunate to be Danielli’s only Ph.D. student at that time, and greatly enjoyed and benefited from Danielli’s friendly and unauthoritarian style of research supervision. Danielli introduced him to David Keilin, whom he came to love and respect more than any other scientist of his acquaintance.
He received the degree of Ph.D. in early 1951 for work on the mode of action of penicillin, and held the post of Demonstrator at the Department of Biochemistry, Cambridge, from 1950 to 1955. In 1955 he was invited by Professor Michael Swann to set up and direct a biochemical research unit, called the Chemical Biology Unit, in the Department of Zoology, Edinburgh University, where he was appointed to a Senior Lectureship in 1961, to a Readership in 1962, and where he remained until acute gastric ulcers led to his resignation after a period of leave in 1963.
From 1963 to 1965, he withdrew completely from scientific research, and acted as architect and master of works, directly supervising the restoration of an attractive Regency-fronted Mansion, known as Glynn House, in the beautiful wooded Glynn Valley, near Bodmin, Cornwall – adapting and furnishing a major part of it for use as a research labotatory. In this, he was lucky to receive the enthusiastic support of his former research colleague Jennifer Moyle. He and Jennifer Moyle founded a charitable company, known as Glynn Research Ltd., to promote fundamental biological research and finance the work of the Glynn Research Laboratories at Glynn House. The original endowment of about £250,000 was donated about equally by Peter Mitchell and his elder brother Christopher John Mitchell.
In 1965, Peter Mitchell and Jennifer Moyle, with the practical help of one technician, Roy Mitchell (unrelated to Peter Mitchell), and with the administrative help of their company secretary, embarked on the programme of research on chemiosmotic reactions and reaction systems for which the Glynn Research Institute has become known. Since its inception, the Glynn Research Institute has not had sufficient financial resources to employ more than three research workers, including the Research Director, on its permanent staff. He has continued to act as Director of Research at the Glynn Research Institute up to the present time. An acute lack of funds has recently led to the possibility that the Glynn Research Institute may have to close.
Beside his interest in communication between molecules, Peter Mitchell has become more and more interested in the problems of communication between individual people in civilised societies, especially in the context of the spread of violence in the increasingly collectivist societies in most parts of the world. His own experience of small and large organisations in the scientific world has led him to regard the small organisations as being, not only more alive and congenial, but also more effective, for many (although perhaps not all) purposes. He would therefore like to have the opportunity to become more deeply involved in studies of the ways in which sympathetic communication and cooperative activity between free and potentially independent people may be improved. One of his specific interests in this field of knowledge is the use of money as an instrument of personal responsibility and of choice in free societies, and the flagrant abuse and basically dishonest manipulation of the system of monetary units of value practised by the governments of most nations.
Peter Mitchell died on April 10, 1992.
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