314 research outputs found
Transition to adult care in Finnish adolescents with juvenile idiopathic arthritis
Objective The symptoms of juvenile idiopathic arthritis (JIA) and the necessity for continuous treatment may persist in adulthood. Therefore, patients with JIA need to be appropriately transferred to adult care. We aimed to analyse the timing of the patients' transition to adult care, and patients' self-management skills with the process and the quality of the transition. Method This study included 161 Finnish participants of the population-based Nordic JIA cohort who attended a 17 year follow-up appointment. Special attention was paid to the three groups: those referred by the paediatric rheumatology outpatient clinic to primary healthcare (PHC), those who were directly transferred to adult rheumatology care, and those who were later referred. Results A total of 136 patients (84%) were eligible to participate in the study, and 40% of them were directly transferred to an adult rheumatology clinic. Of the patients, 72% eventually ended up being referred to an adult rheumatology outpatient clinic. However, 16% of the patients in the PHC group had active disease during the study appointment and were referred to adult services after the study visit. Conclusion This study reveals the need to improve the transition process from paediatric care to adult care and to find the variables that can indicate the need for immediate transition. Although challenging, it is important to avoid treatment delay in adult patients with JIA who may have active disease but who do not have appropriate access to an adult rheumatological outpatient clinic.Peer reviewe
Avoiding BBN Constraints on Mirror Models for Sterile Neutrinos
We point out that in models that explain the LSND result for neutrino
oscillation using the mirror neutrinos, the big bang nucleosynthesis constraint
can be avoided by using the late time phase transition that only helps to mix
the active and the sterile neutrinos. We discuss the astrophysical as well as
cosmological implications of this proposal.Comment: 5 pages, latex; more discussion added; results unchange
Neutrino Mass Texture with Large Mixing
We propose a simple texture for the right-handed Majorana mass matrix to give
a large mixing angle and hierarchical left-handed neutrino
mass pattern. Consistently with the Dirac mass texture of the quark sector
realizing the CKM mixing, this naturally explains the recent experimental
results on both the atmospheric neutrino anomaly observed by the
Superkamiokande collaboration and the solar neutrino problem. In this texture
the right-handed Majorana mass of the third generation is of the order of GUT
scale, which is favorable for reproducing the observed bottom-tau mass ratio.Comment: 10 pages, LaTeX, comments and references adde
Connecting bimaximal neutrino mixing to a light sterile neutrino
It is shown that if small neutrino masses owe their origin to the
conventional seesaw mechanism and the MNS mixing matrix is in the exact
bimaximal form, then there exist symmetries in the theory that allow one of the
righthanded neutrinos to become naturally massless, making it a candidate for
the sterile neutrino discussed in the literature. Departures from the exact
bimaximal limit leads to tiny mass for the sterile neutrino as well as its
mixing to the active neutrinos. This provides a minimal theoretical framework
where a simultaneous explanation of the solar, atmospheric and LSND
observations within the so-called 3+1 scenario may be possible.Comment: new references added; paper accepted for publication in Phys. Rev.
D.(rapid communications); note adde
A comprehensive study of neutrino spin-flavour conversion in supernovae and the neutrino mass hierarchy
Resonant spin-flavour (RSF) conversions of supernova neutrinos, which is
induced by the interaction between the nonzero neutrino magnetic moment and
supernova magnetic fields, are studied for both normal and inverted mass
hierarchy. As the case for the pure matter-induced neutrino oscillation
(Mikheyev--Smirnov--Wolfenstein (MSW) effect), we find that the RSF transitions
are strongly dependent on the neutrino mass hierarchy as well as the value of
. Flavour conversions are solved numerically for various neutrino
parameter sets, with presupernova profile calculated by Woosley and Weaver. In
particular, it is very interesting that the RSF-induced
\nu_\rme\to\bar\nu_\rme transition occurs, if the following conditions are
all satisfied: the value of ( is the neutrino magnetic
moment, and is the magnetic field strength) is sufficiently strong, the
neutrino mass hierarchy is inverted, and the value of is large
enough to induce adiabatic MSW resonance. In this case, the strong peak due to
original \nu_\rme emitted from neutronization burst would exist in time
profile of the neutrino events detected at the Super-Kamiokande detector. If
this peak were observed in reality, it would provide fruitful information on
the neutrino properties. On the other hand, characters of the neutrino spectra
are also different between the neutrino models, but we find that there remains
degeneracy among several models. Dependence on presupernova models is also
discussed.Comment: 23 pages, 11 figures, corrected minor typos, added references. Final
version to appear in Journal of Cosmology and Astroparticle Physic
Light Sterile Neutrino from extra dimensions and Four-Neutrino Solutions to Neutrino Anomalies
We propose a four-neutrino model which can reconcile the existing data coming
from underground experiments in terms of neutrino oscillations, together with
the hint from the LSND experiment and a possible neutrino contribution to the
hot dark matter of the Universe. It applies the idea that extra compact
dimensions, probed only by gravity and possibly gauge-singlet fields, can lower
the fundamental scales such as the Planck, string or unification scales. Our
fourth light neutrino ( for sterile) is identified with the zero
mode of the Kaluza-Klein states. To first approximation \nu_sterile combines
with the nu_mu in order to form a Dirac neutrino with mass in the eV range
leaving the other two neutrinos massless. The smallness of this mass scale
(suitable for LSND and Hot Dark Matter) arises without appealing neither to a
see-saw mechanism nor to a radiative mechanism, but from the volume factor
associated with the canonical normalization of the wave-function of the bulk
field in the compactified dimensions. % On the other hand the splitting between
\nm and \nu_sterile (atmospheric scale) as well as the mass of the two other
neutrinos (solar mass scale) arise from the violation of the fermion number on
distant branes. We also discuss alternative scenarios involving
flavour-changing interactions. In one of them \ne can be in the electron-volt
range and therefore be probed in beta decay studies.Comment: 12 pages, latex, no figures, title changed, final version to be
published in Phys Rev
Neutrino Anomalies and Quasi-Dirac neutrinos
We discuss possibility of describing solar, atmospheric and LSND results with
four neutrinos forming two quasi-degenerate pairs. The simplest versions of
this 2+2 scheme with either or mixing exclusively with
sterile neutrino is disfavored by the SNO and atmospheric neutrino results
respectively. A generalized scheme with sterile state participating in both the
solar and atmospheric oscillations is still allowed. We show thasolar and
atmospheric oscillations is still allowed. We show that the complex pattern of
mixing needed for this purpose follows from a simple L_e+L_\mu-L_\tau-L_s
symmetry. Specific form of L_e+L_\mu-L_\tau-L_s symmetric mass matrix is
determined from experimental results. Two theoretical schemes which lead to
this form and a proper breaking of L_e+L_\mu-L_\tau-L_s symmetry are discussed.Comment: 15 pages, LATEX, minor corrections; addition of few reference
Escape from washing out of baryon number in a two-zero-texture general Zee model compatible with the large mixing angle MSW solution
We propose a two-zero-texture general Zee model, compatible with the large
mixing angle Mikheyev-Smirnov-Wolfenstein solution. The washing out of the
baryon number does not occur in this model for an adequate parameter range. We
check the consistency of a model with the constraints coming from flavor
changing neutral current processes, the recent cosmic microwave background
observation, and the Z-burst scenario.Comment: 22 pages, 2 eps figures, Type set revtex
Supernova Bounds on Majoron-emitting decays of light neutrinos
Neutrino masses arising from the spontaneous violation of ungauged
lepton-number are accompanied by a physical Goldstone boson, generically called
Majoron. In the high-density supernova medium the effects of Majoron-emitting
neutrino decays are important even if they are suppressed in vacuo by small
neutrino masses and/or small off-diagonal couplings. We reconsider the
influence of these decays on the neutrino signal of supernovae in the light of
recent Super-Kamiokande data on solar and atmospheric neutrinos. We find that
majoron-neutrino coupling constants in the range 3\times 10^{-7}\lsim g\lsim
2\times 10^{-5} or g \gsim 3 \times 10^{-4} are excluded by the observation
of SN1987A. Then we discuss the potential of Superkamiokande and the Sudbury
Neutrino Observatory to detect majoron neutrino interactions in the case of a
future galactic supernova. We find that these experiments could probe majoron
neutrino interactions with improved sensitivity.Comment: 28 pages, 5 figure
New Supernova Constraints on Sterile Neutrino Production
We consider the possibility that a light sterile-neutrino species can
be produced by scattering during the cooling of a proto-neutron star.
If we parameterize the sterile neutrino production cross-section by a parameter
as , where is an electron, neutron or proton, we show that is
constrained by limits to the conversion of to in the region
between the sterile-neutrino trapping region and the electron-neutrino trapping
region. This consideration excludes values of in the range between 10^{-4}
\la A \la 10^{-1}.Comment: 12 pages; Late
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