From the Executive Director Kathryn Sullivan to Receive Sigma Xi's Mcgovern Award
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Fotonica Ed Elettronica Quantistica
Fotonica ed elettronica quantistica http://www.dsf.unica.it/~fotonica/teaching/fotonica.html Fotonica ed elettronica quantistica Quantum optics - Quantization of electromagnetic field - Statistics of light, photon counting and noise; - HBT and correlation; g1 e g2 coherence; antibunching; single photons - Squeezing - Quantum cryptography - Quantum computer, entanglement and teleportation Light-matter Interaction - Two-level atom - Laser physics - Spectroscopy - Electronics and photonics at the nanometer scale - Cold atoms - Photodetectors - Solar cells http://www.dsf.unica.it/~fotonica/teaching/fotonica.html Energy Temperature LHC at CERN, Higgs, SUSY, ??? TeV 15 q q particle accelerators 10 K q GeV proton rest mass - quarks 1012K MeV electron rest mass / gamma rays 109K keV Nuclear Fusion, x rays, Sun center 106K Atoms ionize - visible light eV Sun surface fundamental components components fundamental room temperature 103K meV Liquid He, superconductors, space 1K dilution refrigerators, quantum Hall µeV laser-cooled atoms 10-3K neV Bose-Einstein condensates 10-6K peV low T record 480 picokelvin 10-9K -12 complexity, organization organization complexity, 10 K Nobel Prizes in Physics 2010 - Andre Geims, Konstantin Novoselov 2009 - Charles K. Kao, Willard S. Boyle, George E. Smith 2007 - Albert Fert, Peter Gruenberg 2005 - Roy J. Glauber, John L. Hall, Theodor W. Hänsch 2001 - Eric A. Cornell, Wolfgang Ketterle, Carl E. Wieman 1997 - Steven Chu, Claude Cohen-Tannoudji, William D. Phillips 1989 - Norman F. Ramsey, Hans G. Dehmelt, Wolfgang Paul 1981 - Nicolaas Bloembergen, Arthur L. Schawlow, Kai M. Siegbahn 1966 - Alfred Kastler 1964 - Charles H. Townes, Nicolay G. Basov, Aleksandr M. Prokhorov 1944 - Isidor Isaac Rabi 1930 - Venkata Raman 1921 - Albert Einstein 1907 - Albert A. -
Why Joseph Erlanger Rejected the Local Circuit Theory of Nerve Impulse Propagation
Why Joseph Erlanger Rejected the Local Circuit Theory of Nerve Impulse Propagation Greg Gandenberger University of Pittsburgh, Department of History and Philosophy of Science 1017 Cathedral of Learning, Pittsburgh, PA 15260. [email protected] Abstract In the 1920s and 1930s, Joseph Erlanger and his colleagues expressed doubts about the local circuit theory of nerve impulse propagation in some of their publications. In 1934, their scepticism inspired Alan Hodgkin to begin a series of experiments that are generally regarded as providing strong support for the local circuit theory. Hodgkin’s experiments are well known, but the nature and sources of Erlanger’s scepticism are not. In the mid-1920s, Erlanger believed that oscillograph recordings indicated that the eddy currents generated by action currents are too small to propagate the nerve impulse as the local circuit theory proposes. In the 1930s, his fundamental objection to the local circuit theory was his belief that eddy currents large enough to propagate nerve impulses would dissipate a large amount of energy and produce uncontrolled stray effects. However, a 1936 discovery led him to admit that eddy currents do at least increase the excitability of an active fiber ahead of the action current wave. His opposition to the local circuit theory diminished further as a result of several developments between late 1938 and early 1939, including most notably Hodgkin demonstration that the resistance of the medium outside the active nerve affects propagation velocity. Word Count: 7467 Keywords Joseph Erlanger; Alan Hodgkin; local circuit theory; membrane theory; St. Louis School; electrophysiology 1. Introduction Early in his 1934-1935 year as a Cambridge undergraduate, Alan Hodgkin discovered that a blocked nerve impulse increases the excitability of the nerve beyond the block. -
Wave Nature of Matter: Made Easy (Lesson 3) Matter Behaving As a Wave? Ridiculous!
Wave Nature of Matter: Made Easy (Lesson 3) Matter behaving as a wave? Ridiculous! Compiled by Dr. SuchandraChatterjee Associate Professor Department of Chemistry Surendranath College Remember? I showed you earlier how Einstein (in 1905) showed that the photoelectric effect could be understood if light were thought of as a stream of particles (photons) with energy equal to hν. I got my Nobel prize for that. Louis de Broglie (in 1923) If light can behave both as a wave and a particle, I wonder if a particle can also behave as a wave? Louis de Broglie I’ll try messing around with some of Einstein’s formulae and see what I can come up with. I can imagine a photon of light. If it had a “mass” of mp, then its momentum would be given by p = mpc where c is the speed of light. Now Einstein has a lovely formula that he discovered linking mass with energy (E = mc2) and he also used Planck’s formula E = hf. What if I put them equal to each other? mc2 = hf mc2 = hf So for my photon 2 mp = hfhf/c/c So if p = mpc = hfhf/c/c p = mpc = hf/chf/c Now using the wave equation, c = fλ (f = c/λ) So mpc = hc /λc /λc= h/λ λ = hp So you’re saying that a particle of momentum p has a wavelength equal to Planck’s constant divided by p?! Yes! λ = h/p It will be known as the de Broglie wavelength of the particle Confirmation of de Broglie’s ideas De Broglie didn’t have to wait long for his idea to be shown to be correct. -
Famous Physicists Himansu Sekhar Fatesingh
Fun Quiz FAMOUS PHYSICISTS HIMANSU SEKHAR FATESINGH 1. The first woman to 6. He first succeeded in receive the Nobel Prize in producing the nuclear physics was chain reaction. a. Maria G. Mayer a. Otto Hahn b. Irene Curie b. Fritz Strassmann c. Marie Curie c. Robert Oppenheimer d. Lise Meitner d. Enrico Fermi 2. Who first suggested electron 7. The credit for discovering shells around the nucleus? electron microscope is often a. Ernest Rutherford attributed to b. Neils Bohr a. H. Germer c. Erwin Schrödinger b. Ernst Ruska d. Wolfgang Pauli c. George P. Thomson d. Clinton J. Davisson 8. The wave theory of light was 3. He first measured negative first proposed by charge on an electron. a. Christiaan Huygens a. J. J. Thomson b. Isaac Newton b. Clinton Davisson c. Hermann Helmholtz c. Louis de Broglie d. Augustin Fresnel d. Robert A. Millikan 9. He was the first scientist 4. The existence of quarks was to find proof of Einstein’s first suggested by theory of relativity a. Max Planck a. Edwin Hubble b. Sheldon Glasgow b. George Gamow c. Murray Gell-Mann c. S. Chandrasekhar d. Albert Einstein d. Arthur Eddington 10. The credit for development of the cyclotron 5. The phenomenon of goes to: superconductivity was a. Carl Anderson b. Donald Glaser discovered by c. Ernest O. Lawrence d. Charles Wilson a. Heike Kamerlingh Onnes b. Alex Muller c. Brian D. Josephson 11. Who first proposed the use of absolute scale d. John Bardeen of Temperature? a. Anders Celsius b. Lord Kelvin c. Rudolf Clausius d. -
Barbara Mcclintock's World
Barbara McClintock’s World Timeline adapted from Dolan DNA Learning Center exhibition 1902-1908 Barbara McClintock is born in Hartford, Connecticut, the third of four children of Sarah and Thomas Henry McClintock, a physician. She spends periods of her childhood in Massachusetts with her paternal aunt and uncle. Barbara at about age five. This prim and proper picture betrays the fact that she was, in fact, a self-reliant tomboy. Barbara’s individualism and self-sufficiency was apparent even in infancy. When Barbara was four months old, her parents changed her birth name, Eleanor, which they considered too delicate and feminine for such a rugged child. In grade school, Barbara persuaded her mother to have matching bloomers (shorts) made for her dresses – so she could more easily join her brother Tom in tree climbing, baseball, volleyball, My father tells me that at the and football. age of five I asked for a set of tools. He My mother used to did not get me the tools that you get for an adult; he put a pillow on the floor and give got me tools that would fit in my hands, and I didn’t me one toy and just leave me there. think they were adequate. Though I didn’t want to tell She said I didn’t cry, didn’t call for him that, they were not the tools I wanted. I wanted anything. real tools not tools for children. 1908-1918 McClintock’s family moves to Brooklyn in 1908, where she attends elementary and secondary school. In 1918, she graduates one semester early from Erasmus Hall High School in Brooklyn. -
I. Hox Genes 2
School ofMedicine Oregon Health Sciences University CERTIFICATE OF APPROVAL This is certify that the Ph.D. thesis of WendyKnosp has been approved Mentor/ Advisor ~ Member Member QUANTITATIVE ANALYSIS OF HOXA13 FUNCTION IN THE DEVELOPING LIMB By Wendy M. lt<nosp A DISSERTATION Presented to the Department of Molecular and Medical Genetics and the Oregon Health & Science University School of Medicine in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 2006 TABLE OF CONTENTS LIST OF FIGURES iv LIST OF ABBREVIATIONS vii ACKNOWLEDGEMENTS X ABSTRACT xii CHAPTER 1: Introduction 1 I. Hox genes 2 A. Discovery of Hox genes in Drosophila melanogaster 2 B. Hox cluster colinearity and conservation 7 C. Human Hox mutations 9 D. Hoxa13: HFGS and Guttmacher syndromes 10 II. The Homeodomain 12 A. Homeodomain structure 12 B. DNA binding 14 Ill. Limb development 16 A. Patterning of the limb axes 16 B. Digit formation 20 C. lnterdigital programmed cell death 21 IV. BMPs and limb development 23 A. BMP signaling in the limb 23 B. BMP target genes 27 V. Hoxa13 and embryonic development 30 A. The Hoxa13-GFP mouse model 30 B. Hoxa13 mutant phenotypes 34 C. HOXA 13 homeodomain 35 D. HOXA 13 protein-protein interactions 36 E. HOXA 13 target genes 37 VI. Hypothesis and Rationale 39 CHAPTER 2: HOXA13 regulates Bmp2 and Bmp7 40 I. Abstract 42 II. Introduction 43 Ill. Results 46 IV. Discussion 69 v. Materials and Methods 75 VI. Acknowledgements 83 11 CHAPTER 3: Quantitative analysis of HOXA13 function 84 HOXA 13 regulation of Sostdc1 I. -
I. I. Rabi Papers [Finding Aid]. Library of Congress. [PDF Rendered Tue Apr
I. I. Rabi Papers A Finding Aid to the Collection in the Library of Congress Manuscript Division, Library of Congress Washington, D.C. 1992 Revised 2010 March Contact information: http://hdl.loc.gov/loc.mss/mss.contact Additional search options available at: http://hdl.loc.gov/loc.mss/eadmss.ms998009 LC Online Catalog record: http://lccn.loc.gov/mm89076467 Prepared by Joseph Sullivan with the assistance of Kathleen A. Kelly and John R. Monagle Collection Summary Title: I. I. Rabi Papers Span Dates: 1899-1989 Bulk Dates: (bulk 1945-1968) ID No.: MSS76467 Creator: Rabi, I. I. (Isador Isaac), 1898- Extent: 41,500 items ; 105 cartons plus 1 oversize plus 4 classified ; 42 linear feet Language: Collection material in English Location: Manuscript Division, Library of Congress, Washington, D.C. Summary: Physicist and educator. The collection documents Rabi's research in physics, particularly in the fields of radar and nuclear energy, leading to the development of lasers, atomic clocks, and magnetic resonance imaging (MRI) and to his 1944 Nobel Prize in physics; his work as a consultant to the atomic bomb project at Los Alamos Scientific Laboratory and as an advisor on science policy to the United States government, the United Nations, and the North Atlantic Treaty Organization during and after World War II; and his studies, research, and professorships in physics chiefly at Columbia University and also at Massachusetts Institute of Technology. Selected Search Terms The following terms have been used to index the description of this collection in the Library's online catalog. They are grouped by name of person or organization, by subject or location, and by occupation and listed alphabetically therein. -
The Contributions of George Beadle and Edward Tatum
| PERSPECTIVES Biochemical Genetics and Molecular Biology: The Contributions of George Beadle and Edward Tatum Bernard S. Strauss1 Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637 KEYWORDS George Beadle; Edward Tatum; Boris Ephrussi; gene action; history It will concern us particularly to take note of those cases in Genetics in the Early 1940s which men not only solved a problem but had to alter their mentality in the process, or at least discovered afterwards By the end of the 1930s, geneticists had developed a sophis- that the solution involved a change in their mental approach ticated, self-contained science. In particular, they were able (Butterfield 1962). to predict the patterns of inheritance of a variety of charac- teristics, most morphological in nature, in a variety of or- EVENTY-FIVE years ago, George Beadle and Edward ganisms although the favorites at the time were clearly Tatum published their method for producing nutritional S Drosophila andcorn(Zea mays). These characteristics were mutants in Neurospora crassa. Their study signaled the start of determined by mysterious entities known as “genes,” known a new era in experimental biology, but its significance is to be located at particular positions on the chromosomes. generally misunderstood today. The importance of the work Furthermore, a variety of peculiar patterns of inheritance is usually summarized as providing support for the “one gene– could be accounted for by alteration in chromosome struc- one enzyme” hypothesis, but its major value actually lay both ture and number with predictions as to inheritance pattern in providing a general methodology for the investigation of being quantitative and statistical. -
Physics Here at Uva from 1947-49
PHYS 202 Lecture 22 Professor Stephen Thornton April 18, 2005 Reading Quiz Which of the following is most correct? 1) Electrons act only as particles. 2) Electrons act only as waves. 3) Electrons act as particles sometimes and as waves other times. 4) It is not possible by any experiment to determine whether an electron acts as a particle or a wave. Answer: 3 In some cases we explain electron phenomena as a particle –for example, an electron hitting a TV screen. In other cases we explain it as a wave – in the case of a two slit diffraction experiment showing interference. Exam III Wednesday, April 20 Chapters 25-28 20 questions, bring single sheet of paper with anything written on it. Number of questions for each chapter will be proportional to lecture time spent on chapter. Last time Blackbody radiation Max Planck and his hypothesis Photoelectric effect Photons Photon momentum Compton effect Worked Exam 3 problems Today de Broglie wavelengths Particles have wavelike properties Wave-particle duality Heisenberg uncertainty principle Tunneling Models of atoms Emission spectra Work problems Finish last year’s exam problems de Broglie wavelength We saw that light, which we think of as a wave, can have particle properties. Can particles also have wavelike properties? A rule of nature says that if something is not forbidden, then it will probably happen. h λ = all objects p How can we demonstrate these wavelike properties? Typical wavelengths Tennis ball, m = 57 g, v = 60 mph; λ ~ 10-34 m. NOT POSSIBLE to detect!! 50 eV electron; λ ~ 0.2 x 10-9 m or 0.2 nm We need slits of the order of atomic dimensions. -
Norman Borlaug
Norman Borlaug Melinda Smale, Michigan State University I’d like to offer some illustrative examples of how scientific partnerships and exchange of plant genetic resources in international agricultural research have generated benefits for US farmers and consumers. 1. It is widely accepted that the greatest transformation in world agriculture of the last century was the Green Revolution, which averted famine particularly in the wheat and rice-growing areas of numerous countries in Asia by boosting levels of farm productivity several times over, lowering prices for consumers, raising income and demand for goods and services. Most of us here are familiar with the history of this transformation. • You will remember that the key technological impetus was short- statured varieties that were fertilizer responsive and didn’t fall over in the field when more of the plant’s energy was poured into grain rather than the stalk and leaves. • Less well known is that the origin of the genes that conferred short- stature in wheat was a landrace from Korea--transferred to Japan, named Daruma, and bred into Norin 10. Norin 10 was named for a Japanese research station, tenth selection from a cross. Later, Norin 10 was brought as a seed sample by an agronomist advisor who served in the MacArthur campaign after WWII. At Washington State University it was crossed to produce important US wheat varieties. The most extensive use of Norin 10 genes outside Japan and the US was by Norman Borlaug, who won the 1970 Nobel Peace Prize. He was the founder of the World Food Prize (won, for example, by Gebisa Ejeta). -
Tierversuche in Der Forschung Senatskommission Für Tierexperimentelle Forschung Der Deutschen Forschungsgemeinschaft Tierversuche in Der Forschung 2 3
Senatskommission für tierexperimentelle Forschung der Deutschen Forschungsgemeinschaft Tierversuche in der Forschung Senatskommission für tierexperimentelle Forschung der Deutschen Forschungsgemeinschaft Tierversuche in der Forschung 2 3 Inhalt Vorwort . 4 Tierversuche und Tierschutz: Ethische Abwägungen Einführung . 6 Die Entwicklung des Tierschutzgedankens in Deutschland . 39 Ethische Aspekte von Tierversuchen und das Solidaritätsprinzip. 40 Tierversuche: Definition und Zahlen Die Übertragbarkeit aus ethisch-rechtlicher Sicht. 45 Was ist ein Tierversuch? . 9 Das 3 R-Prinzip . 48 Wie viele Tiere werden verwendet? . 9 Alternativen zum Tierversuch. 51 Wofür werden Tiere in der Forschung benötigt? . 11 Grenzen von Alternativmethoden. 54 Welche Tierarten werden eingesetzt? . 11 Die Basler Deklaration . 56 Europaweite Entwicklung . 14 Tierversuche in Deutschland: Vom Antrag bis zur Durchführung Tierexperimentelle Praxis: Einsatzbereiche für Versuchstiere Europäische Regelungen für Tierversuche . 59 Grundlagenforschung. 17 Tierversuche unter Genehmigungsvorbehalt . 60 Medizinische Forschung. 18 Rechtliche Grundlagen . 60 Nobelpreiswürdig: Herausragende wissenschaftliche Erkenntnisse . 20 Genehmigungsverfahren . 63 Diagnostik . 22 Durchführung von Tierversuchen . 64 Transplantationsmedizin . 25 Qualifizierte Überwachung. 68 Zell- und Gewebeersatz beim Menschen. 26 Belastungen für die Tiere . 69 Stammzellforschung . 27 Die Tierschutz-Verbandsklage . 71 Genomforschung . 28 Neurowissenschaften . 31 Anhang Veterinärmedizinische Forschung . 33 Tierversuche -
Appendix E Nobel Prizes in Nuclear Science
Nuclear Science—A Guide to the Nuclear Science Wall Chart ©2018 Contemporary Physics Education Project (CPEP) Appendix E Nobel Prizes in Nuclear Science Many Nobel Prizes have been awarded for nuclear research and instrumentation. The field has spun off: particle physics, nuclear astrophysics, nuclear power reactors, nuclear medicine, and nuclear weapons. Understanding how the nucleus works and applying that knowledge to technology has been one of the most significant accomplishments of twentieth century scientific research. Each prize was awarded for physics unless otherwise noted. Name(s) Discovery Year Henri Becquerel, Pierre Discovered spontaneous radioactivity 1903 Curie, and Marie Curie Ernest Rutherford Work on the disintegration of the elements and 1908 chemistry of radioactive elements (chem) Marie Curie Discovery of radium and polonium 1911 (chem) Frederick Soddy Work on chemistry of radioactive substances 1921 including the origin and nature of radioactive (chem) isotopes Francis Aston Discovery of isotopes in many non-radioactive 1922 elements, also enunciated the whole-number rule of (chem) atomic masses Charles Wilson Development of the cloud chamber for detecting 1927 charged particles Harold Urey Discovery of heavy hydrogen (deuterium) 1934 (chem) Frederic Joliot and Synthesis of several new radioactive elements 1935 Irene Joliot-Curie (chem) James Chadwick Discovery of the neutron 1935 Carl David Anderson Discovery of the positron 1936 Enrico Fermi New radioactive elements produced by neutron 1938 irradiation Ernest Lawrence