105 research outputs found
Video-rate terahertz digital holographic imaging system
Terahertz (THz) imaging has been demonstrated in numerous applications from medical to non-destructive evaluation (NDE), but current systems require expensive components, provide slow frame-rates and low resolutions. THz holography offers a potentially low-cost, high-performance alternative. Here we demonstrate the first full video-rate THz digital holography system at 2.52 THz (118.8 µm) using low-cost optical components. 2D digital reconstructions of samples are performed at frame-rates of 50 Hz - an order of magnitude higher than previous systems, whilst imaging of samples concealed in common packaging types demonstrates suitability for NDE applications. A lateral resolution of 250 µm was determined using a 1951 USAF target
The Japanese model in retrospective : industrial strategies, corporate Japan and the 'hollowing out' of Japanese industry
This article provides a retrospective look at the Japanese model of industrial development. This model combined an institutional approach to production based around the Japanese Firm (Aoki's, J-mode) and strategic state intervention in industry by the Japanese Ministry of International Trade and Industry (MITI). For a long period, the alignment of state and corporate interests appeared to match the wider public interest as the Japanese economy prospered. However, since the early 1990s, the global ambitions of the corporate sector have contributed to a significant 'hollowing out' of Japan's industrial base. As the world today looks for a new direction in economic management, we suggest the Japanese model provides policy-makers with a salutary lesson in tying the wider public interest with those of the corporate sector
Search for antihelium in cosmic rays
The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle
Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320
and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity
range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper
limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure
Protons in near earth orbit
The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured
by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at
an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is
parameterized by a power law. Below the geomagnetic cutoff a substantial second
spectrum was observed concentrated at equatorial latitudes with a flux ~ 70
m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated
trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure
A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01
The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics
experiment that will study cosmic rays in the to range and will be installed on the International Space Station
(ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the
space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected
cosmic ray triggers. Part of the \emph{Mir} space station was within the
AMS-01 field of view during the four day \emph{Mir} docking phase of this
flight. We have reconstructed an image of this part of the \emph{Mir} space
station using secondary and emissions from primary cosmic rays
interacting with \emph{Mir}. This is the first time this reconstruction was
performed in AMS-01, and it is important for understanding potential
backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor
stylistic and grammer change
The Fueling and Evolution of AGN: Internal and External Triggers
In this chapter, I review the fueling and evolution of active galactic nuclei
(AGN) under the influence of internal and external triggers, namely intrinsic
properties of host galaxies (morphological or Hubble type, color, presence of
bars and other non-axisymmetric features, etc) and external factors such as
environment and interactions. The most daunting challenge in fueling AGN is
arguably the angular momentum problem as even matter located at a radius of a
few hundred pc must lose more than 99.99 % of its specific angular momentum
before it is fit for consumption by a BH. I review mass accretion rates,
angular momentum requirements, the effectiveness of different fueling
mechanisms, and the growth and mass density of black BHs at different epochs. I
discuss connections between the nuclear and larger-scale properties of AGN,
both locally and at intermediate redshifts, outlining some recent results from
the GEMS and GOODS HST surveys.Comment: Invited Review Chapter to appear in LNP Volume on "AGN Physics on All
Scales", Chapter 6, in press. 40 pages, 12 figures. Typo in Eq 5 correcte
Improving the reach of vaccines to low-resource regions, with a needle-free vaccine delivery device and long-term thermostabilization
Dry-coated microprojections can deliver vaccine to abundant antigen-presenting cells in the skin and induce efficient immune responses and the dry-coated vaccines are expected to be thermostable at elevated temperatures. In this paper, we show that we have dramatically improved our previously reported gas-jet drying coating method and greatly increased the delivery efficiency of coating from patch to skin to from 6.5% to 32.5%, by both varying the coating parameters and removing the patch edge. Combined with our previous dose sparing report of influenza vaccine delivery in a mouse model, the results show that we now achieve equivalent protective immune responses as intramuscular injection (with the needle and syringe), but with only 1/30th of the actual dose. We also show that influenza vaccine coated microprojection patches are stable for at least 6 months at 23 degrees C. inducing comparable immunogenicity with freshly coated patches. The dry-coated microprojection patches thus have key and unique attributes in ultimately meeting the medical need in certain low-resource regions with low vaccine affordability and difficulty in maintaining "cold-chain" for vaccine storage and transport. (C) 2011 Elsevier B.V. All rights reserved
Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01
A measurement of the cosmic ray positron fraction e+/(e+ + e-) in the energy range of 1-30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from positrons
Measurement of event-shape observables in Z→ℓ+ℓ− events in pp collisions at √ s=7 TeV with the ATLAS detector at the LHC
Event-shape observables measured using charged particles in inclusive
-boson events are presented, using the electron and muon decay modes of the
bosons. The measurements are based on an integrated luminosity of of proton--proton collisions recorded by the ATLAS detector at the
LHC at a centre-of-mass energy TeV. Charged-particle
distributions, excluding the lepton--antilepton pair from the -boson decay,
are measured in different ranges of transverse momentum of the boson.
Distributions include multiplicity, scalar sum of transverse momenta, beam
thrust, transverse thrust, spherocity, and -parameter, which are
in particular sensitive to properties of the underlying event at small values
of the -boson transverse momentum. The Sherpa event generator shows larger
deviations from the measured observables than Pythia8 and Herwig7. Typically,
all three Monte Carlo generators provide predictions that are in better
agreement with the data at high -boson transverse momenta than at low
-boson transverse momenta and for the observables that are less sensitive to
the number of charged particles in the event.Comment: 36 pages plus author list + cover page (54 pages total), 14 figures,
4 tables, submitted to EPJC, All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2014-0
Transforming growth factor-β1 inhibits synthesis of cytokines in endotoxin-stimulated human whole blood.
OBJECTIVE: To determine the potency of transforming growth factor-beta (TGF-beta) for inhibiting proinflammatory cytokine synthesis in endotoxin-stimulated human whole blood. DESIGN: Endotoxin-stimulated whole blood from healthy volunteers as an ex vivo model of endotoxemia was incubated with different concentrations of TGF-beta 1. Cytokine levels in plasma with a bioassay (for tumor necrosis factor alpha) or an enzyme-linked immunosorbent assay (for interleukin [IL]-1 beta and IL-6), messenger RNA (mRNA) expression with northern blotting, and protein levels with Western blotting were determined. RESULTS: High TGF-beta 1 concentrations (> 100 pg/mL) inhibited (P < .05) secretion of tumor necrosis factor alpha, IL-1 beta, and IL-6 into lipopolysaccharide-stimulated whole blood, while low concentrations (< 50 pg/mL) were ineffective. Moreover, TGF-beta 1 inhibited mRNA expression of tumor necrosis factor alpha and IL-6 in a dose-dependent manner. In contrast, neither IL-1 beta mRNA expression nor IL-1 beta protein synthesis were attenuated by TGF-beta 1. CONCLUSION: Transforming growth factor-beta 1, with its downregulatory effect on the synthesis and release of proinflammatory cytokines by phagocytic cells, represents an inhibitor of endotoxin-induced inflammatory reactions
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