557 research outputs found
Generalized event shape and energy flow studies in e[superscript +]e[superscript −] annihilation at √s = 91.2−208.0 GeV
No full textWe present results from a study of hadronic event structure in high energy e[superscript +]e[superscript −] interactions using the L3 detector at LEP. A new class of event shape distributions are measured at and above the Z boson pole for light quark (u, d, s, c) flavours. Energy flow correlations are studied for all hadronic events. Next-to-leading-log QCD calculations and QCD models with improved leading-log approximations are compared to data and good agreement is found at the Z-pole whereas some discrepancies are observed at higher centre-of-mass energies
Exercise Performance vs. Growth of Haemopoietic Stem Cells Amount in CUWs Blood after Noninvasive Modulation
No full textWe've reported earlier about spontaneous regular fluctuations of concentration of the CD34+-cells recorded in the blood of Chernobyl cleanup workers (CUWs) in remote period of time and about an opportunity of artificial growth of the previously mentioned parameter by transcutaneous vibrational impact on awake medullary hemopoiesis zones. The current research aims at studying interfacing of CUWs exercise performance indices and of the amount of haemopoietic stem cells in their peripheral blood after vibroacoustic influence.
Materials: A random sampling of CUWs under long-term dispensary observation (40 male patients, aged 50 on average) have been examined under dispensary conditions.
Methods: A course of vibroacoustic mobilization of autologous haemopoietic stem cells into the bloodstream from the bone marrow haemopoietic zones has been conducted with the purpose of correction of CUWs psychosomatic condition. The CUWs exercise performance has been examined via veloergometric exercise ECG testing before the modulation course and 3 to 6 months later on. CD34+-cell subpopulation in peripheral blood was estimated by laser cross flow-cytometry method (FACScan, Beckton-Dickinson) with monoclones (DAKO, BD) before and right after the end of the modulation course.
Results: For a cluster of patients examined, certain increase in the number of CD34+-cells in the blood right after the end of the modulation course has been discovered. Dynamic tracking (3 to 6 months) of this cluster has revealed certain increase in the number of patients capable of fulfilling the exercise ECG test; maximal oxygen uptake for all the patients of this cluster has also shown certain increase in the same period of time. On the contrary, increase of the reviewed indices were uncertain for those patients, who did not demonstrate any growth of the amount of CD34+-cells right after the modulation course.
Conclusions: For a distinct cluster of examined patients, interfacing has been discovered in between growth of the amount of CD34+-cells into their peripheral bloodstream right after the course of noninvasive vibroacoustic modulation and increase of the showings of their exercise performance in 3 to 6 months
ISOTOPIC COMPOSITION OF LIGHT NUCLEI IN COSMIC RAYS: RESULTS FROM AMS-01
No full textThe variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we present measurements of the isotopic ratios [superscript 2]H/[superscript 4]He, [superscript 3]He/[superscript 4]He, [superscript 6]Li/[superscript 7]Li, [superscript 7]Be/([superscript 9]Be+[superscript 10]Be), and [superscript 10]B/[superscript 11]B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.United States. Dept. of EnergyMassachusetts Institute of Technolog
Measurement of the inclusive charmless semileptonic branching fraction of beauty hadrons and a determination of vertical bar V-ub vertical bar at LEP RID C-4549-2008 RID C-5719-2008
No full textA measurement of the inclusive charmless semileptonic branching fraction of beauty hadrons, b --> X-u l nu, has been performed using almost two million hadronic Z decays collected by the L3 experiment at LEP, yielding the result: Br(b --> X-u l nu) = (3.3 +/- 1.0 +/- 1.7) x 10(-3). The first uncertainty is statistical and the second is systematic. The modulus of the Cabibbo-Kobayashi-Maskawa matrix element V-ub extracted from this measurement is: V-ub = (6.0(-1.0-1.9)(+0.8+1.4) +/- 0.2) x 10(-3), where the uncertainties are statistical, systematic and theoretical, respectively. (C) 1998 Elsevier Science B.V. All rights reserved
Индукция циркулирующих CD133+ стволовых лимфоцитов, коммитированных к ткани печени, у пациентов из листа ожидания трансплантации
No full textStudies on the regenerative capabilities of tissues have shown that damaged liver can recover using hematopoietic stem cells (HSCs), which are able not only to replace cells in the target organ, but can also deliver trophic factors that support endogenous liver regeneration. There is practically no data on how organ-derived humoral signals involve such morphogenic/trophic cells in circulation. Objective: to investigate the role of non-invasive vibromechanical percutaneous action on the liver in cirrhosis by quantification of CD133+ lymphoid HSCs with specific hepatic marker alpha-fetoprotein (AFP) in patients awaiting liver transplantation. Materials and methods. In order to increase the number of AFP+ part of CD133+ stem lymphoid cells in the blood, the patient’s cirrhotic liver was mechanically activated by transcutaneous microvibration using electromagnetic vibrophones in contact with the skin. This generated mechanical impulses with a 10 μm amplitude and a smoothly varying frequency from 0.03 kHz to 18 kHz and back to within one cycle lasting 1 minute. The amount of AFP+ lymphocyte fraction in the total content of CD133+ HSCs in lymphocytes of potential recipients was monitored by flow cytometry before and during daily 15-minute sonication of the skin zone corresponding to the liver projection for three weeks with eight synphased vibraphones. Results. Sonication of the liver projection zone significantly increased the number of liver-specific CD133+ AFP+ lymphocytes by 2–3 times compared to the baseline values. Repeated similar sonication of the same site after a three-week break showed a statistically insignificant increase from the initial level. With a similar effect on the spinal projection in the control group of waitlisted patients with cirrhosis, there was no increase in CD133+ AFP+ lymphocytes. Conclusion. Mechanical stress prompts the organ to secrete specific humoral signals that provoke the bone marrow to produce additional lymphoid stem cells committed to the liver and recruit them into circulation.Исследования регенераторных возможностей тканей доказали восстановление поврежденной печени с помощью стволовых гемопоэтических клеток (СГК), которые способны не только замещать клетки в органе-мишени, но также могут доставлять трофические факторы, поддерживающие эндогенную регенерацию печени. Данных о том, как органопроизводные гуморальные сигналы вовлекают такие морфогенные/трофические клетки в циркуляцию, практически нет. Цель: исследовать роль неинвазивного вибро-механического чрескожного воздействия на печень при циррозе с помощью количественного учета в крови фракции CD133+ гемопоэтических стволовых клеток лимфоидного ряда со специфическим печеночным маркером альфа-фетопротеином (АФП) у больных, ожидающих трансплантацию печени. Методы. Для повышения в крови числа АФП-позитивной части CD133+ стволовых лимфоидных клеток механически активировали цирротическую печень пациента путем чрескожной микровибрации с помощью контактирующих с кожей электромагнитных виброфонов, генерирующих механические импульсы амплитудой 10 мкм и плавно меняющейся частотой от 0,03 Гц до 18 кГц и обратно в течение одного цикла продолжительностью 1 минута. Количество АФП-положительной фракции лимфоцитов в общем содержании CD133+ СГК в лимфоцитах потенциальных реципиентов контролировали методом проточной цитометрии до и во время ежедневного 15-минутного сонирования кожной зоны, соответствующей проекции печени, в течение трех недель, восемью синфазированными виброфонами. Результаты. Звуковое воздействие на зону проекции печени достоверно увеличило количество печеночно-специфических АФП-позитивных CD133+ лимфоцитов крови в 2–3 раза по сравнению с базовыми значениями. Повторное аналогичное сонирование той же зоны после трехнедельного перерыва показало статистически не значимое превышение исходного уровня. При аналогичном воздействии на проекцию позвоночника в контрольной группе больных циррозом печени из листа ожидания феномен увеличения альфа-фетопротеин-позитивных CD133+ лимфоцитов не возникал. Вывод. Механический стресс побуждает орган секретировать специфические гуморальные сигналы, провоцирующие костный мозг производить дополнительные коммитированные к печени стволовые лимфоидные клетки и рекрутировать их в циркуляцию
Search for Heavy Isosinglet Neutrino in Annihilation at LEP
No full textWe report on a search for the first generation heavy neutrino that is an isosinglet under the standard gauge group. The data collected with the L3 detector at center-of-mass energies between 130~\hbox{\rm\ Ge\kern -0.1em V} and 208~\hbox{\rm\ Ge\kern -0.1em V} are used. The decay channel is investigated and no evidence is found for a heavy neutrino, , in a mass range between 80~\hbox{\rm\ Ge\kern -0.1em V} and 205~\hbox{\rm\ Ge\kern -0.1em V}. Upper limits on the mixing parameter between the heavy and light neutrino are derived.We report on a search for the first generation heavy neutrino that is an isosinglet under the standard SU (2) L gauge group. The data collected with the L3 detector at center-of-mass energies between 130 GeV and 208 GeV are used. The decay channel N e →eW is investigated and no evidence is found for a heavy neutrino, N e , in a mass range between 80 GeV and 205 GeV. Upper limits on the mixing parameter between the heavy and light neutrino are derived.We report on a search for the first generation heavy neutrino that is an isosinglet under the standard SU(2)_L gauge group. The data collected with the L3 detector at center-of-mass energies between 130 GeV and 208 GeV are used.The decay channel N_e --> eW is investigated and no evidence is found for a heavy neutrino, N_e, in a mass range between 80 GeV and 205 GeV. Upper limits on the mixing parameter between the heavy and light neutrino are derived
Measurement of the Running of the Fine-Structure Constant
No full textSmall-angle Bhabha scattering data recorded at the Z resonance and large-angleBhabha scattering data recorded at \textrm{Ge\kern -0.1em V} bythe L3 detector at LEP are used to measure the running of the effective fine-structure constant for spacelike momentum transfers. The results are\begin{eqnarray*} \alpha^{-1}(-2.1 \mathrm{Ge\kern -0.1em V}^{2}) - \alpha^{-1}(-6.25 \mathrm{Ge\kern -0.1em V}^{2}) & = & 0.78 \pm 0.26 \\ \alpha^{-1}(-12.25 \mathrm{Ge\kern -0.1em V}^{2}) - \alpha^{-1}(-3434 \mathrm{Ge\kern -0.1em V}^{2}) & = & 3.80 \pm 1.29, \\\end{eqnarray*}in agreement with theoretical predictions.Small-angle Bhabha scattering data recorded at the Z resonance and large-angle Bhabha scattering data recorded at s =189 GeV by the L3 detector at LEP are used to measure the running of the effective fine-structure constant for spacelike momentum transfers. The results are α −1 (−2.1 GeV 2 )−α −1 (−6.25 GeV 2 )=0.78±0.26 α −1 (−12.25 GeV 2 )−α −1 (−3434 GeV 2 )=3.80±1.29, in agreement with theoretical predictions.Bhabha scattering data recorded at \sqrt{s}=189 GeV by the L3 detector at LEP are used to measure the running of the effective fine-structure constant for spacelike momentum transfers. The results are alpha^-1(-2.1 GeV^2) - alpha^-1(-6.25 GeV^2) = 0.78 +/- 0.26 alpha^-1(-12.25 GeV^2) - alpha^-1(-3434 GeV^2) = 3.80 +/- 1.29, in agreement with theoretical predictions
formation in two-photon collisions at LEP
No full textTwo-photon formation of the charmonium resonance has been studied with the L3 detector at LEP. The is identified through its decay , with a subsequent decay or . With an integrated luminosity of 140 pb at 91~\textrm{Ge\kern -0.1em V} and 52 pb at {Ge\kern -0.1em V}, we measure the two-photon width of the to be \begin{center} \Gamma_{\gamma\gamma}(\chi_{{\rm c}2})=1.02 \pm 0.40 \mbox{\;(stat.)} \pm 0.15 \mbox{\;(sys.)} \pm 0.09(\rm{BR.}) {\mathrm{\ ke\kern -0.1em V}}
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