364 research outputs found
Influence of the nonlinearity parameter on the solar-wind sub-ion magnetic energy spectrum: FLR-Landau fluid simulations
The cascade of kinetic Alfv\'en waves (KAWs) at the sub-ion scales in the
solar wind is numerically simulated using a fluid approach that retains ion and
electron Landau damping, together with ion finite Larmor radius corrections.
Assuming initially equal and isotropic ion and electron temperatures, and an
ion beta equal to unity, different simulations are performed by varying the
propagation direction and the amplitude of KAWs that are randomly driven at a
transverse scale of about one fifth of the proton gyroradius in order to
maintain a prescribed level of turbulent fluctuations. The resulting turbulent
regimes are characterized by the nonlinearity parameter, defined as the ratio
of the characteristic times of Alfv\'en wave propagation and of the transverse
nonlinear dynamics. The corresponding transverse magnetic energy spectra
display power laws with exponents spanning a range of values consistent with
spacecraft observations. The meandering of the magnetic field lines together
with the ion temperature homogenization along these lines are shown to be
related to the strength of the turbulence, measured by the nonlinearity
parameter. The results are interpreted in terms of a recently proposed
phenomenological model where the homogenization process along field lines
induced by Landau damping plays a central role
Reactor Fuel Fraction Information on the Antineutrino Anomaly
We analyzed the evolution data of the Daya Bay reactor neutrino experiment in
terms of short-baseline active-sterile neutrino oscillations taking into
account the theoretical uncertainties of the reactor antineutrino fluxes. We
found that oscillations are disfavored at with respect to a
suppression of the reactor antineutrino flux and at
with respect to variations of the and
fluxes. On the other hand, the analysis of the rates of the
short-baseline reactor neutrino experiments favor active-sterile neutrino
oscillations and disfavor the suppression of the flux at
and variations of the and fluxes
at . We also found that both the Daya Bay evolution data and the
global rate data are well-fitted with composite hypotheses including variations
of the or fluxes in addition to
active-sterile neutrino oscillations. A combined analysis of the Daya Bay
evolution data and the global rate data shows a slight preference for
oscillations with respect to variations of the and
fluxes. However, the best fits of the combined data are given
by the composite models, with a preference for the model with an enhancement of
the flux and relatively large oscillations.Comment: 9 page
Influence of ion-to-electron temperature ratio on tearing instability and resulting subion-scale turbulence in a low- collisionless plasma
A two-field gyrofluid model including ion finite Larmor radius (FLR)
corrections, magnetic fluctuations along the ambient field and electron inertia
is used to study two-dimensional reconnection in a low collisionless
plasma, in a plane perpendicular to the ambient field. Both moderate and large
values of the ion-to-electron temperature ratio are considered. The
linear growth rate of the tearing instability is computed for various values of
, confirming the convergence to reduced electron magnetodynamics (REMHD)
predictions in the large limit. Comparisons with analytical estimates in
several limit cases are also presented. The nonlinear dynamics leads to a
fully-developed turbulent regime that appears to be sensitive to the value of
the parameter . For , strong large-scale velocity shears
trigger Kelvin-Helmholtz instability, leading to the propagation of the
turbulence through the separatrices, together with the formation of eddies of
size of the order of the electron skin depth. In the regime, the
vortices are significantly smaller and their accurate description requires that
electron FLR effects be taken into account
A NOVEL FUSION 5'AFF3/3'BCL2 ORIGINATED FROM A t(2;18)(Q11.2-Q21.33) TRANSLOCATION IN FOLLICULAR LYMPHOMA
Follicular lymphoma is the second most frequent type of non-Hodgkin's lymphoma in adults. The basic molecular defect consists of the t(14;18)(q32;q21) translocation, juxtaposing the B-cell lymphoma protein 2 gene BCL2 to the immunoglobulin heavy chain locus IGH@, and leading to the antiapoptotic BCL2 protein overproduction. Variations in the t(14;18) are rare and can be classified into two categories: (i) simple variants, involving chromosomes 18 and 2, or 22, in which the fusion partner of BCL2 is the light-chain IGK@ or IGL@; (ii) complex variant translocations occurring among chromosomes 14, 18 and other chromosomes. We report a follicular lymphoma case showing BCL2 overexpression, detected by immunohistochemistry and real-time quantitative PCR, consequently to the formation of a novel fusion gene between the 5' of the lymphoid nuclear transcriptional activator gene AFF3 at 2q11.2, and the 3' of BCL2. This case shows evidence, for the first time, of BCL2 overexpression consequently to the fusion of BCL2 to a non-IG partner locus
nu_e Disappearance in MiniBooNE
The anomalous excess of low-energy nu_e events measured in the MiniBooNE
experiment is explained through a renormalization of the absolute neutrino flux
and a simultaneous disappearance of the nu_e's in the beam, which is compatible
with that indicated by the results of Gallium radioactive source experiments.
We present the results of the fit of MiniBooNE data (P(nu_e->nu_e) = 0.64 +0.08
-0.07) and the combined fit of MiniBooNE data and the nu_e disappearance
measured in the Gallium radioactive source experiments, which gives
P(nu_e->nu_e) = 0.82 +- 0.04. We show that our interpretation of the data is
also compatible with an old indication in favor of nu_e disappearance found
from the analysis of the results of beam-dump experiments, leading to
P(nu_e->nu_e) = 0.80 +0.03 -0.04.Comment: 17 pages. Final version published in Phys. Rev. D 77, 093002 (2008
EUROnu-WP6 2010 Report
This is a summary of the work done by the Working Package 6 (Physics) of the
EU project "EUROnu" during the second year of activity of the project.Comment: 82 pages, 51 eps figure
FATZ, a filamin-, actinin-, and telethonin-binding protein of the Z-disc of skeletal muscle
We report the identification and characterization of a novel 32-kDa protein expressed in skeletal muscle and located in the Z-disc of the sarcomere. We found that this protein binds to three other Z-disc proteins; therefore, we have-named it FATZ, gamma -filamin/ABP-L, alpha -actinin and telethonin binding protein of the Z-disc. From yeast two-hybrid experiments we are able to show that the SR3-SR4 domains of alpha -actinin 2 are required to bind the COOH-terminal region of the FATZ as does gamma -filamin/ABP-L, Furthermore, by using a glutathione S-transferase overlay assay we find that FATZ also binds telethonin. The level of FATZ protein in muscle cells increases during differentiation, being clearly detectable before the onset of myosin, Although FATZ has no known interaction domains, it would appear to be involved in a complex network of interactions with other Z-band components. On the basis of the information known about its binding partners, we could envisage a central role for FATZ in the: myofibrillogenesis, After screening our muscle expressed sequence tag data base and the public expressed sequence tag data bases, we were able to assemble two other muscle transcripts that show a high level of identity with FATZ in two different domains. Therefore, FATZ may be the first member of a small family of novel muscle proteins
Summary report of MINSIS workshop in Madrid
Recent developments on tau detection technologies and the construction of
high intensity neutrino beams open the possibility of a high precision search
for non-standard {\mu} - {\tau} flavour transition with neutrinos at short
distances. The MINSIS - Main Injector Non-Standard Interaction Search- is a
proposal under discussion to realize such precision measurement. This document
contains the proceedings of the workshop which took place on 10-11 December
2009 in Madrid to discuss both the physics reach as well as the experimental
requirements for this proposal.Comment: Proceedings of the MINSIS Workshop, Dec 10-11, 2009 in Madrid. 15
pages late
Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS
Tensions in several phenomenological models grew with experimental results on
neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent,
carefully recomputed, antineutrino fluxes from nuclear reactors. At a
refurbished SBL CERN-PS facility an experiment aimed to address the open issues
has been proposed [1], based on the technology of imaging in ultra-pure
cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of
the physics case was performed. We tackled specific physics models and we
optimized the neutrino beam through a full simulation. Experimental aspects not
fully covered by the LAr detection, i.e. the measurements of the lepton charge
on event-by-event basis and their energy over a wide range, were also
investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino
interactions play an important role in disentangling different phenomenological
scenarios provided their charge state is determined. Also, the study of muon
appearance/disappearance can benefit of the large statistics of CC muon events
from the primary neutrino beam. Results of our study are reported in detail in
this proposal. We aim to design, construct and install two Spectrometers at
"NEAR" and "FAR" sites of the SBL CERN-PS, compatible with the already proposed
LAr detectors. Profiting of the large mass of the two Spectrometers their
stand-alone performances have also been exploited.Comment: 70 pages, 38 figures. Proposal submitted to SPS-C, CER
A narrow band neutrino beam with high precision flux measurements
The ENUBET facility is a proposed narrow band neutrino beam where lepton
production is monitored at single particle level in the instrumented decay
tunnel. This facility addresses simultaneously the two most important
challenges for the next generation of cross section experiments: a superior
control of the flux and flavor composition at source and a high level of
tunability and precision in the selection of the energy of the outcoming
neutrinos. We report here the latest results in the development and test of the
instrumentation for the decay tunnel. Special emphasis is given to irradiation
tests of the photo-sensors performed at INFN-LNL and CERN in 2017 and to the
first application of polysiloxane-based scintillators in high energy physics.Comment: Poster presented at NuPhys2017 (London, 20-22 December 2017). 5
pages, 2 figure
- âŠ