566 research outputs found
THERAPEUTIC MANAGEMENT OF SARCOPTIC MANGE IN RABBIT WITH IVERMECTIN
Sarcoptic mange infected non-descriptive rabbits were successfully treated with
Ivermectin @ 400 ”g / kg body weight sub-cutaneously once weekly for 4 weeks resulted
complete recovery within a month in Kalyani area, West Bengal, India
The Absorptive Extra Dimensions
It is well known that gravity and neutrino oscillation can be used to probe
large extra dimensions in a braneworld scenario. We argue that neutrino
oscillation remains a useful probe even when the extra dimensions are small,
because the brane-bulk coupling is likely to be large. Neutrino oscillation in
the presence of a strong brane-bulk coupling is vastly different from the usual
case of a weak coupling. In particular, some active neutrinos could be absorbed
by the bulk when they oscillate from one kind to another, a signature which can
be taken as the presence of an extra dimension. In a very large class of models
which we shall discuss, the amount of absorption for all neutrino oscillations
is controlled by a single parameter, a property which distinguishes extra
dimensions from other mechanisms for losing neutrino fluxes.Comment: Introduction enlarged; conclusions added. To appear in Phys. Rev.
Possible Z-width probe of a "brane-world" scenario for neutrino masses
The possibility that the accurately known value of the Z width might furnish
information about the coupling of two neutrinos to the Majoron (Nambu-Goldstone
boson of spontaneous lepton number violation) is proposed and investigated in
detail. Both the "ordinary" case and the case in which one adopts a "brane"
world picture with the Majoron free to travel in extra dimensions are studied.
Bounds on the dimensionless coupling constants are obtained, allowing for any
number of extra dimensions and any intrinsic mass scale. These bounds may be
applied to a variety of different Majoron models. If a technically natural
see-saw model is adopted, the predicted coupling constants are far below these
upper bounds. In addition, for this natural model, the effect of extra
dimensions is to decrease the predicted partial Z width, the increase due to
many Kaluza-Klein excitations being compensated by the decrease of their common
coupling constant.Comment: RevTeX, 12 pages, 3 figure
Transient Approach to Radiative Heat Transfer Free Convection Flow with Ramped Wall Temperature
The effect of radiation on natural convection incompressible viscous fluid near a vertical flat plate with ramped wall
temperature has been studied. An analytical solution of the governing equation has been obtained by employing
Laplace transform technique. It is examined that two different solutions for the fluid velocities, one valid for fluids of
Prandtl number Pr different from 1 Ra , Ra being the radiation parameter and the other for which the Prandtl
number equal to 1 Ra . The variations of velocities and fluid temperature are presented graphically. Furthermore,
the radiative heat transfer on natural convection flow near a ramped plate temperature has been compared with the
flow near a plate with the constant wall temperature. It is found that an increase in radiation parameter leads to rise
the fluid velocity as well as temperature
Minimal SUSY SO(10) model and predictions for neutrino mixings and leptonic CP violation
We discuss a minimal Supersymmetric SO(10) model where B-L symmetry is broken
by a {\bf 126} dimensional Higgs multiplet which also contributes to fermion
masses in conjunction with a {\bf 10} dimensional superfield. This minimal
Higgs choice provides a partial unification of neutrino flavor structure with
that of quarks and has been shown to predict all three neutrino mixing angles
and the solar mass splitting in agreement with observations, provided one uses
the type II seesaw formula for neutrino masses. In this paper we generalize
this analysis to include arbitrary CP phases in couplings and vevs. We find
that (i) the predictions for neutrino mixings are similar with as before and other parameters in a somewhat bigger range and (ii) that
to first order in the quark mixing parameter (the Cabibbo angle), the
leptonic mixing matrix is CP conserving. We also find that in the absence of
any higher dimensional contributions to fermion masses, the CKM phase is
different from that of the standard model implying that there must be new
contributions to quark CP violation from the supersymmetry breaking sector.
Inclusion of higher dimensional terms however allows the standard model CKM
phase to be maintained.Comment: 22 pages, 6 figure
Exchange anisotropy, disorder and frustration in diluted, predominantly ferromagnetic, Heisenberg spin systems
Motivated by the recent suggestion of anisotropic effective exchange
interactions between Mn spins in GaMnAs (arising as a result of
spin-orbit coupling), we study their effects in diluted Heisenberg spin
systems. We perform Monte Carlo simulations on several phenomenological model
spin Hamiltonians, and investigate the extent to which frustration induced by
anisotropic exchanges can reduce the low temperature magnetization in these
models and the interplay of this effect with disorder in the exchange. In a
model with low coordination number and purely ferromagnetic (FM) exchanges, we
find that the low temperature magnetization is gradually reduced as exchange
anisotropy is turned on. However, as the connectivity of the model is
increased, the effect of small-to-moderate anisotropy is suppressed, and the
magnetization regains its maximum saturation value at low temperatures unless
the distribution of exchanges is very wide. To obtain significant suppression
of the low temperature magnetization in a model with high connectivity, as is
found for long-range interactions, we find it necessary to have both
ferromagnetic and antiferromagnetic (AFM) exchanges (e.g. as in the RKKY
interaction). This implies that disorder in the sign of the exchange
interaction is much more effective in suppressing magnetization at low
temperatures than exchange anisotropy.Comment: 9 pages, 8 figure
Intranuclear Inclusions of Expanded Polyglutamine Protein in Spinocerebellar Ataxia Type 3
AbstractThe mechanism of neurodegeneration in CAG/polyglutamine repeat expansion diseases is unknown but is thought to occur at the protein level. Here, in studies of spinocerebellar ataxia type 3, also known as Machado-Joseph disease (SCA3/MJD), we show that the disease protein ataxin-3 accumulates in ubiquitinated intranuclear inclusions selectively in neurons of affected brain regions. We further provide evidence in vitro for a model of disease in which an expanded polyglutamine-containing fragment recruits full-length protein into insoluble aggregates. Together with recent findings from transgenic models, our results suggest that intranuclear aggregation of the expanded protein is a unifying feature of CAG/polyglutamine diseases and may be initiated or catalyzed by a glutamine-containing fragment of the disease protein
Generating Neutrino Mass in the 331 Model
A mechanism for generating small tree-level Majorana mass for neutrinos is
implemented in the 331 Model. No additional fermions or scalars need to be
added, and no mass scale greater than a few TeV is invoked.Comment: LaTex, 7 pages, no figures. Revised version to appear in Phys. Rev.
On 'Light' Fermions and Proton Stability in 'Big Divisor' D3/D7 Swiss Cheese Phenomenology
Building up on our earlier work [1,2], we show the possibility of generating
"light" fermion mass scales of MeV-GeV range (possibly related to first two
generations of quarks/leptons) as well as eV (possibly related to first two
generations of neutrinos) in type IIB string theory compactified on
Swiss-Cheese orientifolds in the presence of a mobile space-time filling
D3-$brane restricted to (in principle) stacks of fluxed D7-branes wrapping the
"big" divisor \Sigma_B. This part of the paper is an expanded version of the
latter half of section 3 of a published short invited review [3] written up by
one of the authors [AM]. Further, we also show that there are no SUSY GUT-type
dimension-five operators corresponding to proton decay, as well as estimate the
proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be
10^{61} years. Based on GLSM calculations in [1] for obtaining the geometric
Kaehler potential for the "big divisor", using further the Donaldson's
algorithm, we also briefly discuss in the first of the two appendices,
obtaining a metric for the Swiss-Cheese Calabi-Yau used, that becomes Ricci
flat in the large volume limit.Comment: v2: 1+25 pages, Title modified and text thoroughly expanded including
a brief discussion on obtaining Ricci-flat Swiss Cheese Calabi-Yau metrics
using the Donaldson's algorithm, references added, to appear in EPJ
An SO(10) GUT Model With Lopsided Mass Matrix and Neutrino Mixing Angle theta_13
An alternative supersymmetric SO(10) grand unification model with lopsided
fermion mass matrices is introduced. It generates a large solar-neutrino-mixing
angle through the neutrinos' Dirac mass matrix constrained by the SO(10) group
structure, avoiding the fine-tuning required in the Majorana mass matrix of
right-handed neutrinos. The model fits well the known data on masses and
mixings of quarks and leptons, and predicts a sizable lepton mixing
, which is significantly larger than that of
the original lopsided model.Comment: 9 page
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