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Airway T Cells Induced by Pulmonary DNA Immunization Mediate Protective Anti-Viral Immunity
Vaccination strategies for protection against a number of respiratory pathogens must induce T-cell populations in both the pulmonary airways and peripheral lymphoid organs. In this study, we show that pulmonary immunization using plasmid DNA formulated with the polymer polyethyleneimine (PEI-DNA) induced antigen-specific T cells in the airways that persisted long after antigen local clearance. The persistence of the cells was not mediated by local lymphocyte proliferation or persistent antigen presentation within the lung or airways. These vaccine-induced T cells effectively mediated protective immunity against respiratory challenges with vaccinia virus and influenza virus. Moreover, this protection was not dependent upon the recruitment of T cells from peripheral sites. These findings demonstrate that pulmonary immunization with PEI-DNA is an efficient approach for inducing robust pulmonary T-cell populations that are effective at protecting against respiratory pathogens
Positive pion absorption on 3He using modern trinucleon wave functions
We study pion absorption on 3He employing trinucleon wave functions
calculated from modern realistic NN interactions (Paris, CD Bonn). Even though
the use of the new wave functions leads to a significant improvement over older
calculations with regard to both cross section and polarization data, there are
hints that polarization data with quasifree kinematics cannot be described by
just two-nucleon absorption mechanisms.Comment: 14 pages, 6 figure
Experimental evaluation of an adaptive Joule--Thomson cooling system including silicon-microfabricated heat exchanger and microvalve components
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98726/1/JVA021005.pd
Search for the Flavor-Changing Neutral-Current Decays and
We report the results of a search for the flavor-changing neutral-current
decays and in
data from Fermilab charm hadroproduction experiment E791. No signal above
background is found, and we obtain upper limits on branching fractions,
and
, at the 90\% confidence
level.Comment: nine pages with figures; compressed, uuencoded postscrip
Measurement of the Ds Lifetime
We report the results of a precise measurement of the Ds meson lifetime based
on 1662 +/- 56 fully reconstructed Ds -> phi pi decays, from the charm
hadroproduction experiment E791 at Fermilab. Using an unbinned maximum
likelihood fit, we measure the Ds lifetime to be 0.518 +/- 0.014 +/- 0.007 ps.
The ratio of the measured Ds lifetime to the world average D0 lifetime is 1.25
+/- 0.04. This result differs from unity by six standard deviations, indicating
significantly different lifetimes for the Ds and the D0.Comment: 12 pages, 3 figures, 2 table. LaTe
Direct measurement of the pion valence quark momentum distribution, the pion light-cone wave function squared
We present the first direct measurements of the pion valence quark momentum
distribution which is related to the square of the pion light-cone wave
function. The measurements were carried out using data on diffractive
dissociation of 500 GeV/c into di-jets from a platinum target at
Fermilab experiment E791. The results show that the light-cone
asymptotic wave function, which was developed using perturbative QCD methods,
describes the data well for or more. We also
measured the transverse momentum distribution of the diffractive di-jets.Comment: 13 pages, 4 figure
Study of the decay and measurement of masses and widths
From a sample of 848 44 decays, we find
. Using a Dalitz plot analysis of this
three body decay, we find significant contributions from the channels
, , , , and
. We present also the values obtained for masses and widths of
the resonances and .Comment: 10 pages, 3 eps figure
Experimental evidence for a light and broad scalar resonance in decay
From a sample of decay, we find
. Using a coherent amplitude analysis
to fit the Dalitz plot of this decays, we find strong evidence that a scalar
resonance of mass MeV/ and width MeV/ accounts for approximately half of all decays.Comment: 10 pages, 3 eps figure
Dalitz Plot Analysis of the Decay D^+ --> K^- pi^+ pi^+ and Indication of a Low-Mass Scalar K pi Resonance
We study the Dalitz plot of the decay D^+ --> K^- pi^+ pi^+ with a sample of
15090 events from Fermilab experiment E791. Modeling the decay amplitude as the
coherent sum of known K pi resonances and a uniform nonresonant term, we do not
obtain an acceptable fit. If we allow the mass and width of the K^*_0(1430) to
float, we obtain values consistent with those from PDG but the chi^2 per degree
of freedom of the fit is still unsatisfactory. A good fit is found when we
allow for the presence of an additional scalar resonance, with mass 797 +/- 19
+/- 43 MeV/c^2 and width 410 +/- 43 +/- 87 MeV/c^2. The mass and width of the
K^*_0(1430) become 1459 +/- 7 +/- 5 MeV/c^2 and 175 +/- 12 +/- 12 MeV/c^2,
respectively. Our results provide new information on the scalar sector in
hadron spectroscopy.Comment: Accepted for publication in Physical Review Letter
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