•The genome of influenza A viruses is able to encode up to seven accessory proteins.•Influenza A viruses use alternative splicing, leaky ribosomal scanning, re-initiation, and ribosomal frameshifting ...mechanisms.•Influenza A virus accessory proteins are PB1-F2, PB1-N40, PA-X, PA-N155, PA-N182, M42, NS3.
Influenza A virus is one of the major human pathogens. Despite numerous efforts to produce absolutely effective anti-influenza drugs or vaccines, no such agent has been developed yet. One of the main reasons for this complication is the high mutation rate and the specific structure of influenza A viruses genome. For more than 25 years since the first mapping of the viral genome, it was believed that its 8 genome segments encode 10 proteins. However, the proteome of influenza A viruses has turned out to be much more complex than previously thought. In 2001, the first accessory protein, PB1-F2, translated from the alternative open reading frame, was discovered. Subsequently, six more proteins, PB1-N40, PA-X, PA-N155, PA-N182, M42, and NS3, have been found. It is important to pay close attention to these novel proteins in order to evaluate their role in the pathogenesis of influenza, especially in the case of outbreaks of human infections with new avian viruses, such as H5N1 or H7N9. In this review we summarize the data on the molecular mechanisms used by influenza A viruses to expand their proteome and on the possible functions of the recently discovered viral proteins.
We study an asymptotic behaviour of parametric autoresonance for nonlinear equation. Main result of this work is statement about asymptotic behaviour of measure for captured trajectories. We show ...that the measure is bounded for infinite time interval. To find this, we obtain an asymptotic expansion for capture and asymptotic behaviour of split separatrices for intermediate small amplitudes. In this study, we have used two scaling method for studying the interval of capture. We reduce the problem to equation which defines the separatrix splitting and apply Melnikov’s theory to define the splitting of the separatrices. The obtained result shows important difference between parametric and nonparametric autoresonance, because the measure for captured trajectories for nonparametric autoresonance is not bounded.
Two cases of degeneration of elliptic functions are well known: degeneration into trigonometric functions and degeneration into hyperbolic functions. Approximations of elliptic functions in a ...neighborhood of a degeneration are usually examined by means of series in the modulus of the elliptic function. For applications of the theory of elliptic functions in the theory of dynamical systems, uniform approximations with respect to the modulus and the independent variable are important. This review contains methods for constructing uniform asymptotics.
Differential cross sections for p-Ni56 and p-Ni58 elastic scattering, measured at low momentum transfer and at projectile energies of about 400 MeV/u with beams stored in the Experimental Storage ...Ring (ESR) at GSI, Darmstadt, have been analyzed up to |t|=0.06 (GeV/c)2 applying the model-independent Sum-of-Gaussians (SOG) method based on the Glauber multiple-scattering theory. The rms point matter radius of the self-conjugate doubly magic radioactive Ni56 nucleus was deduced to be 3.62(6) fm, to be compared to the known radius of the stable Ni58 nucleus, 3.67(7) fm. Although the radii of both nuclei differ only slightly, and there is close agreement of the matter radii of Ni58 from former analyses using phenomenological parametrizations of the matter distribution, the SOG method was capable of elucidating pronounced differences in the shapes of the radial matter distributions between both nuclei. Consequences for the understanding of nuclear structure in the vicinity of the N=Z=28 magic shell are briefly discussed.
This study is devoted to the investigation of tunneling superconductor–insulator–superconductor (SIS) Josephson junctions with a new type of shunt based on an additional ...superconductor–insulator–normal metal (SIN) junction placed around the SIS junction. In the course of study, the parameters of such shunted junctions are numerically calculated and their current–voltage characteristics (IVC) are simulated. The designed structures are assembled in real samples and their parameters are studied; the IVC of junctions with different degrees of shunting are measured, and the behavior of these junctions under the influence of high-frequency signals in the subterahertz range is studied.
Quantum electrodynamics in very strong Coulomb fields is one scope which has not yet been tested experimentally with sufficient accuracy to really determine whether the perturbative approach is ...valid. One sensitive test is the determination of the 1s Lamb shift in highly-charged very heavy ions. The 1s Lamb shift of hydrogen-like lead (Pb81+) and gold (Au78+) has been determined using the novel detector concept of silicon microcalorimeters for the detection of hard x-rays. The results of ( 260 53 ) eV for lead and ( 211 42 ) eV for gold are within the error bars in good agreement with theoretical predictions. To our knowledge, for hydrogen-like lead, this represents the most accurate determination of the 1s Lamb shift.
The proton-removal mechanism of the 12C→11B reaction induced on a carbon target via elementary nucleon-nucleon scattering is investigated in exclusive triple-coincidence measurements. The observed ...two-nucleon angular correlations are found to be consistent with quasi-free scattering of a projectile-like proton off a target-like nucleon. Exclusive cross sections for one-step pp and pn interactions are determined as σpp=17.2(12) mb and σpn=18.2(18), respectively. The extracted quasi-free component amounts up to 58(4)% of the total proton-removal cross section. The results are compared to total proton-removal cross sections obtained from the experiment and eikonal reaction theory.
The unexplained disagreement in the dependence of spectroscopic factors
(
C
2
S
exp
)
on the binding energy obtained by nucleon knockout using different targets is still a puzzle that needs to be ...addressed.
To find an explanation of this riddle through exclusive measurements using different targets.
The exclusive measurements were performed by using a
Ne
17
beam with an energy of 500 MeV/u incident on
C
and
CH
2
targets. Through the standard theoretical approach,
C
2
S
exp
were derived from the analysis of the experimental data on proton ejection from the proton halo in
Ne
17
as well as from its core
O
15
.
For the
C
target, proton ejection from the proton halo gave
C
2
S
exp
about 37% smaller than for the
H
target. But when protons are ejected from the core of
Ne
17
,
C
2
S
exp
are identical within statistical uncertainties.
An explanation for the difference in
C
2
S
exp
could be the removal of both halo protons, a more important reaction pathway for the
C
target. The
C
2
S
exp
values obtained by analyzing the proton ejection from the core indicate that it is not affected by the interaction with the halo protons.
Published by the American Physical Society
2024
A variant of the physical mechanism of long-range tropospheric VHF wave propagation is discussed, the justification of which is based on the application of the model coherence parameter describing ...the structure of the electromagnetic field beyond radio horizon formed by wave reflections from quasi-planar boundaries of mesoscale tropospheric inhomogeneities arbitrarily oriented in space.
The H7 system was populated in the H2(He8,He3)H7 reaction with a 26 AMeV He8 beam. The H7 missing mass energy spectrum, the H3 energy and angular distributions in the H7 decay frame were ...reconstructed. The H7 missing mass spectrum shows a peak, which can be interpreted either as unresolved 5/2+ and 3/2+ doublet or one of these states at 6.5(5) MeV. The data also provide indications of the 1/2+ ground state of H7 located at 1.8(5) MeV with quite a low population cross section of ∼25 μb/sr within angular range θc.m.≃(17°-27°).
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