449 research outputs found

    Photon polarization version of the GHz-Mermin Gedanken

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    We have defined a photon polarization analog of the Greenberger, Horne, and Zeilinger (GHZ) experiment that was initially proposed for spin-1/2 quanta. Analogs of the ket states and Pauli spin matrix operators are presented

    Application of a picosecond soft x-ray source to time-resolved plasma dynamics

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    We demonstrate the application of an ultrashort x-ray source as an external probe to measure plasma dynamics. The plasma is generated by a 100-fs Ti:sapphire laser focused onto thin metallic films. Time-resolved spectroscopy of the gold x-ray probe transmission through a perturbed 1000 Å aluminum film reveals redshifts of the LL-shell photoabsorption edge. We show that the dynamic behavior of this shift is consistent with the relaxation of the aluminum following the compression generated by a shock wave traveling through the film. An analytic plasma model, with comparison to a numerical hydrodynamics model, indicates compression up to 1.4 times solid density. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69766/2/APPLAB-70-3-312-1.pd

    New experimental test of Bell inequalities by the use of a non-maximally entangled photon state

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    We report on the first realisation of a test of Bell inequalities using non-maximally entangled states. It is based on the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisations. We discuss the advantages and the possible developments of this configuration.Comment: accepted for publicatio

    Einstein-Podolsky-Rosen-Bohm experiment and Bell inequality violation using Type 2 parametric down conversion

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    We report a new two-photon polarization correlation experiment for realizing the Einstein-Podolsky-Rosen-Bohm (EPRB) state and for testing Bell-type inequalities. We use the pair of orthogonally-polarized light quanta generated in Type 2 parametric down conversion. Using 1 nm interference filters in front of our detectors, we observe from the output of a 0.5mm beta - BaB2O4 (BBO) crystal the EPRB correlations in coincidence counts, and measure an associated Bell inequality violation of 22 standard deviations. The quantum state of the photon pair is a polarization analog of the spin-1/2 singlet state

    The photon: Experimental emphasis on its wave-particle duality

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    Two types of Einstein-Podolsky-Rosen experiments were demonstrated recently in our laboratory. It is interesting to see that in an interference experiment (wave-like experiment) the photon exhibits its particle property, and in a beam-splitting experiment (particle-like experiment) the photon exhibits its wave property. The two-photon states are produced from Type 1 and Type 2 optical spontaneous parametric down conversion, respectively

    Primary prevention of beta-cell autoimmunity and type 1 diabetes - The Global Platform for the Prevention of Autoimmune Diabetes (GPPAD) perspectives.

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    OBJECTIVE: Type 1 diabetes can be identified by the presence of beta-cell autoantibodies that often arise in the first few years of life. The purpose of this perspective is to present the case for primary prevention of beta-cell autoimmunity and to provide a study design for its implementation in Europe. METHODS: We examined and summarized recruitment strategies, enrollment rates, and outcomes in published TRIGR, FINDIA and BABYDIET primary prevention trials, and the TEDDY intensive observational study. A proposal for a recruitment and implementation strategy to perform a phase II/III primary prevention randomized controlled trial in infants with genetic risk for developing beta-cell autoimmunity is outlined. RESULTS: Infants with a family history of type 1 diabetes (TRIGR, BABYDIET, TEDDY) and infants younger than age 3 months from the general population (FINDIA, TEDDY) were enrolled into these studies. All studies used HLA genotyping as part of their eligibility criteria. Predicted beta-cell autoimmunity risk in the eligible infants ranged from 3% (FINDIA, TEDDY general population) up to 12% (TRIGR, BABYDIET). Amongst eligible infants, participation was between 38% (TEDDY general population) and 97% (FINDIA). Outcomes, defined as multiple beta-cell autoantibodies, were consistent with predicted risks. We subsequently modeled recruitment into a randomized controlled trial (RCT) that could assess the efficacy of oral insulin treatment as adapted from the Pre-POINT pilot trial. The RCT would recruit infants with and without a first-degree family history of type 1 diabetes and be based on general population genetic risk testing. HLA genotyping and, for the general population, genotyping at additional type 1 diabetes susceptibility SNPs would be used to identify children with around 10% risk of beta-cell autoimmunity. The proposed RCT would have 80% power to detect a 50% reduction in multiple beta-cell autoantibodies by age 4 years at a two-tailed alpha of 0.05, and would randomize around 1160 infants to oral insulin or placebo arms in order to fulfill this. It is estimated that recruitment would require testing of between 400,000 and 500,000 newborns or infants. CONCLUSION: It is timely and feasible to establish a platform for primary prevention trials for type 1 diabetes in Europe. This multi-site European infrastructure would perform RCTs, supply data coordination and biorepository, provide cohorts for mechanistic and observational studies, and increase awareness for autoimmune diabetes.This work was supported by The Leona M. & Harry B. Helmsley Charitable Trust Grants #2015PG-T1D072 and #2015PG-T1D071.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.molmet.2016.02.00

    First experimental test of Bell inequalities performed using a non-maximally entangled state

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    We report on the realisation of a new test of Bell inequalities using the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisation. The produced state is non-maximally entangled. We discuss the advantages and the possible developments of this configuration

    Semi-Phenomenological Analysis of Dynamics of Nonlinear Excitations in One-Dimensional Electron-Phonon System

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    The structure of moving nonlinear excitations in one-dimensional electron-phonon systems is studied semi-phenomenologically by using an effective action in which the width of the nonlinear excitation is treated as a dynamical variable. The effective action can be derived from Su, Schrieffer and Heeger's model or its continuum version proposed by Takayama, Lin-Liu and Maki with an assumption that the nonlinear excitation moves uniformly without any deformation except the change of its width. The form of the action is essentially the same as that discussed by Bishop and coworkers in studying the dynamics of the soliton in polyacetylene, though some details are different. For the moving excitation with a velocity vv, the width is determined by minimizing the effective action. A requirement that there must be a minimum in the action as a function of its width provides a maximum velocity. The velocity dependence of the width and energy can be determined. The motions of a soliton in p olyacetylene and an acoustic polaron in polydiacetylene are studied within this formulation. The obtained results are in good agreement with those of numerical simulations.Comment: 19 pages, LaTeX, 7 Postscript figures, to be published in J. Phys. Soc. Jpn. vol.65 (1996) No.

    МИРГОРОДСЬКИЙ ПОЛК В РОСІЙСЬКО-ТУРЕЦЬКІЙ ВІЙНІ 1735-1739 РР.

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    Тема пропонованої шановному читачеві статті знаходиться на перетині воєнної історії та краєзнавства. Після тривалої неуваги, зараз воєнна історія, зокрема козаччини, розробляється досить динамічно. Варто згадати хоча б роботи І.Стороженка [1], В.Заруби [2], О.Сокирка [3], Г.Шпитальова [4]. Одночасно все ще не розроблена докладно воєнна історія полків, які складали Гетьманщину. Хоча спроби такого роду є [5], але вони зосереджені не стільки на воєнній історії, скільки на історії полку загалом і, на жаль, не представлені у вигляді монографічних досліджень та не викладені в Інтернеті, що суттєво ускладнює доступ до результатів таких досліджень. Сюжет, пов’язаний із участю Миргородського полку в російсько-турецькій війні 1735-1739 років, не знайшов висвітлення в історіографії, хоча деякі факти містять дослідження А.Байова [6], О.Апанович [7] та вже згадувана монографія Г.Шпитальова. Протягом війни Миргородський полк брав участь як у далеких виправах, так і в ближніх походах різного роду – фортифікаційних, тривожних, для планової охорони кордонів. Залучення козаків Миргородського полку до далеких походів розпочалося вже у червні 1735 р., коли всі полки (крім Стародубського та Чернігівського) вирушили до фортеці Святого Іоанна на Українській лінії, де мали збиратися для виправи на Крим. До прибуття на лінію генерального осавула Ф.Лисенка обов’язки командира цього з’єднання виконував миргородський полковник Павло Апостол [8]. Кількість козаків Миргородського полку, які вирушили в цей похід, точно невідома. Проте є дані щодо старшини, яка очолила виправу – полковник П.Апостол, суддя Ф.Остроградський, писар В.Тихонович, осавул А.Волевач, хорунжі Т.Калницький та К.Шкурка [9]. Згідно з планами Генеральної військової канцелярії (далі – ГВК) передбачалося для Кримської (1736) виправи мобілізувати 16001 гетьманця, в тому числі 1196 шабель Миргородського полку [10]. Виникли певні проблеми з залученням старшини. Наприклад, миргородський обозний С.Родзянка уперто відмовлявся від походу під приводом хвороби, в яку полковник абсолютно не вірив. Проте С.Родзянка апелював до ГВК, де знайшов підтримку. Врешті, полкова старшина миргородців у цій виправі була представлена тими ж постатями, що й 1735 р., лише осавула А.Волевача замінив його колега С.Ґалаґан [11]. За попередніми планами на 1737 р. Миргородський полк мав виставити 849 шабель у Кримський похід. Після рішення фельдмаршала Мініха залишити слобідських козаків для охорони кордону їм на заміну залучили ще 200 миргородців [12]. На цьому зміни не закінчилися. На вимогу фельдмаршала Мініха Миргородський полк перейшов у його підпорядкування і вирушив замість Кримського в Очаківський похід
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