1,663 research outputs found
Accountant and the investor
Professor Custis suggested that I talk on the ethical obligations of the accountant to the investor. The suggestion offered an opportunity to discuss before a sympathetic audience some of those phases of accounting practice which make it, to me, the most attractive of the professions which are closely allied with business; and an opportunity, also, to discuss some questions possessing a broader interest
Methods of taxing war profits compared
To the Editor of The New York Times: In the discussion of the pending finance bill reference is frequently made to the taxation of war profits in England. In general the position is stated to be that in England 80 per cent. of the excess profits are taken by the government, and there is, broadly speaking, no complaint, whereas here it is claimed that substantially lower rates of taxation will work incalculable harm to industry
Relative resistance of HIV-1 founder viruses to control by interferon-alpha
Background: Following mucosal human immunodeficiency virus type 1 (HIV-1) transmission, type 1 interferons
(IFNs) are rapidly induced at sites of initial virus replication in the mucosa and draining lymph nodes. However, the
role played by IFN-stimulated antiviral activity in restricting HIV-1 replication during the initial stages of infection is
not clear. We hypothesized that if type 1 IFNs exert selective pressure on HIV-1 replication in the earliest stages of
infection, the founder viruses that succeed in establishing systemic infection would be more IFN-resistant than viruses
replicating during chronic infection, when type 1 IFNs are produced at much lower levels. To address this hypothesis,
the relative resistance of virus isolates derived from HIV-1-infected individuals during acute and chronic infection to
control by type 1 IFNs was analysed.
Results: The replication of plasma virus isolates generated from subjects acutely infected with HIV-1 and molecularly
cloned founder HIV-1 strains could be reduced but not fully suppressed by type 1 IFNs in vitro. The mean IC50 value for
IFNα2 (22 U/ml) was lower than that for IFNÎČ (346 U/ml), although at maximally-inhibitory concentrations both IFN subtypes
inhibited virus replication to similar extents. Individual virus isolates exhibited differential susceptibility to inhibition by IFNα2
and IFNÎČ, likely reflecting variation in resistance to differentially up-regulated IFN-stimulated genes. Virus isolates
from subjects acutely infected with HIV-1 were significantly more resistant to in vitro control by IFNα than virus
isolates generated from the same individuals during chronic, asymptomatic infection. Viral IFN resistance declined
rapidly after the acute phase of infection: in five subjects, viruses derived from six-month consensus molecular clones
were significantly more sensitive to the antiviral effects of IFNs than the corresponding founder viruses.
Conclusions: The establishment of systemic HIV-1 infection by relatively IFNα-resistant founder viruses lends strong
support to the hypothesis that IFNα plays an important role in the control of HIV-1 replication during the earliest stages
of infection, prior to systemic viral spread. These findings suggest that it may be possible to harness the antiviral activity
of type 1 IFNs in prophylactic and potentially also therapeutic strategies to combat HIV-1 infection
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
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