5,622 research outputs found
Production of a Discrete, Infectious, Double-stranded DNA by Reverse Transcription in Virions of Moloney Murine Leukemia Virus
One of the most unique viral replication schemes is that of the retroviruses (a class that includes the RNA tumor viruses). These viruses synthesize a double-stranded (DS) DNA copy of their single-stranded (SS) RNA genome as the initial event following infection of susceptible cells (see Weinberg 1977). The details of this process—called reverse transcription—are still obscure, but the general outlines have become clear during the last few years
The ground-based FTIR network's potential for investigating the atmospheric water cycle
We present tropospheric H<sub>2</sub><sup>16</sup>O and HD<sup>16</sup>O/H<sub>2</sub><sup>16</sup>O vapour profiles measured by ground-based FTIR (Fourier Transform Infrared) spectrometers between 1996 and 2008 at a northern hemispheric subarctic and subtropical site (Kiruna, Northern Sweden, 68&deg; N and Izaña, Tenerife Island, 28&deg; N, respectively). We compare these measurements to an isotope incorporated atmospheric general circulation model (AGCM). If the model is nudged towards meteorological fields of reanalysis data the agreement is very satisfactory on time scales ranging from daily to inter-annual. Taking the Izaña and Kiruna measurements as an example we document the FTIR network's unique potential for investigating the atmospheric water cycle. At the subarctic site we find strong correlations between the FTIR data, on the one hand, and the Arctic Oscillation index and the northern Atlantic sea surface temperature, on the other hand. The Izaña FTIR measurements reveal the importance of the Hadley circulation and the Northern Atlantic Oscillation index for the subtropical middle/upper tropospheric water balance. We document where the AGCM is able to capture these complexities of the water cycle and where it fails
Pressure-induced and Composition-induced Structural Quantum Phase Transition in the Cubic Superconductor (Sr/Ca)_3Ir_4Sn_{13}
We show that the quasi-skutterudite superconductor Sr_3Ir_4Sn_{13} undergoes
a structural transition from a simple cubic parent structure, the I-phase, to a
superlattice variant, the I'-phase, which has a lattice parameter twice that of
the high temperature phase. We argue that the superlattice distortion is
associated with a charge density wave transition of the conduction electron
system and demonstrate that the superlattice transition temperature T* can be
suppressed to zero by combining chemical and physical pressure. This enables
the first comprehensive investigation of a superlattice quantum phase
transition and its interplay with superconductivity in a cubic charge density
wave system.Comment: 4 figures, 5 pages (excluding supplementary material). To be
published in Phys. Rev. Let
Hard X-ray PHA System for Study on Energetic Electron Tail Formation in ECRH Plasma of Heliotron J
Dilaton Black Holes with Electric Charge
Static spherically symmetric solutions of the Einstein-Maxwell gravity with
the dilaton field are described. The solutions correspond to black holes and
are generalizations of the previously known dilaton black hole solution. In
addition to mass and electric charge these solutions are labeled by a new
parameter, the dilaton charge of the black hole. Different effects of the
dilaton charge on the geometry of space-time of such black holes are studied.
It is shown that in most cases the scalar curvature is divergent at the
horizons. Another feature of the dilaton black hole is that there is a finite
interval of values of electric charge for which no black hole can exist.Comment: 20 pages, LaTeX file + 1 figure, CALT-68-1885. (the postscript file
is improved
The Future of Neutrino Mass Measurements: Terrestrial, Astrophysical, and Cosmological Measurements in the Next Decade. Highlights of the NuMass 2013 Workshop. Milano, Italy, February 4 - 7, 2013
The third Workshop of the NuMass series ("The Future of Neutrino Mass
Measurements: Terrestrial, Astrophysical, and Cosmological Measurements in the
Next Decade: NuMass 2013") was held at Dipartimento di Fisica "G. Occhialini,
University of Milano-Bicocca in Milano, Italy, on 4-7 February 2013. The goal
of this international workshop was to review the status and future of direct
and indirect neutrino mass measurements in the laboratory as well as from
astrophysical and cosmological observations. This paper collects most of the
contributions presented during the Workshop
Reversals in nature and the nature of reversals
The asymmetric shape of reversals of the Earth's magnetic field indicates a
possible connection with relaxation oscillations as they were early discussed
by van der Pol. A simple mean-field dynamo model with a spherically symmetric
coefficient is analysed with view on this similarity, and a comparison
of the time series and the phase space trajectories with those of paleomagnetic
measurements is carried out. For highly supercritical dynamos a very good
agreement with the data is achieved. Deviations of numerical reversal sequences
from Poisson statistics are analysed and compared with paleomagnetic data. The
role of the inner core is discussed in a spectral theoretical context and
arguments and numerical evidence is compiled that the growth of the inner core
might be important for the long term changes of the reversal rate and the
occurrence of superchrons.Comment: 24 pages, 12 figure
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