1,939 research outputs found
Reconciling the CAST and PVLAS Results
The PVLAS experiment has recently claimed evidence for an axion-like particle
in the milli-electron-Volt mass range with a coupling to two photons that
appears to be in contradiction with the negative results of the CAST experiment
searching for solar axions. The simple axion interpretation of these two
experimental results is therefore untenable and it has posed a challenge for
theory. We propose a possible way to reconcile these two results by postulating
the existence of an ultralight pseudo-scalar particle interacting with two
photons and a scalar boson and the existence of a low scale phase transition in
the theory.Comment: 4 pages, 2 figures; references update
Simple Finite Non-Abelian Flavor Groups
The recently measured unexpected neutrino mixing patterns have caused a
resurgence of interest in the study of finite flavor groups with two- and
three-dimensional irreducible representations. This paper details the
mathematics of the two finite simple groups with such representations, the
Icosahedral group A_5, a subgroup of SO(3), and PSL_2(7), a subgroup of SU(3).Comment: 42 pages, matches published version, references adde
Tight junction physiology of pleural mesothelium
Pleura consists of visceral and parietal cell layers, producing a fluid, which
is necessary for lubrication of the pleural space. Function of both
mesothelial cell layers is necessary for the regulation of a constant pleural
fluid volume and composition to facilitate lung movement during breathing.
Recent studies have demonstrated that pleural mesothelial cells show a
distinct expression pattern of tight junction proteins which are known to
ubiquitously determine paracellular permeability. Most tight junction proteins
provide a sealing function to epithelia, but some have been shown to have a
paracellular channel function or ambiguous properties. Here we provide an in-
depth review of the current knowledge concerning specific functional
contribution of these proteins determining transport and barrier function of
pleural mesothelium
A Supersymmetric U(1)' Model with Multiple Dark Matters
We consider a scenario where a supersymmetric model has multiple dark matter
particles. Adding a U(1)' gauge symmetry is a well-motivated extension of the
Minimal Supersymmetric Standard Model (MSSM). It can cure the problems of the
MSSM such as the mu-problem or the proton decay problem with high-dimensional
lepton number and baryon number violating operators which R-parity allows. An
extra parity (U-parity) may arise as a residual discrete symmetry after U(1)'
gauge symmetry is spontaneously broken. The Lightest U-parity Particle (LUP) is
stable under the new parity becoming a new dark matter candidate. Up to three
massive particles can be stable in the presence of the R-parity and the
U-parity. We numerically illustrate that multiple stable particles in our model
can satisfy both constraints from the relic density and the direct detection,
thus providing a specific scenario where a supersymmetric model has
well-motivated multiple dark matters consistent with experimental constraints.
The scenario provides new possibilities in the present and upcoming dark matter
searches in the direct detection and collider experiments.Comment: 25 pages, 5 figure
Management of anticoagulant-related intracranial hemorrhage: An evidence-based review
The increased use of anticoagulants for the prevention and treatment of thromboembolic diseases has led to a rising incidence of anticoagulant-related intracranial hemorrhage (AICH) in the aging western population. High mortality accompanies this form of hemorrhagic stroke, and significant and debilitating long-term consequences plague survivors. Although management guidelines for such hemorrhages are available for the older generation anticoagulants, they are still lacking for newer agents, which are becoming popular among physicians. Supportive care, including blood pressure control, and reversal of anticoagulation remain the cornerstone of acute management of AICH. Prothrombin complex concentrates are gaining popularity over fresh frozen plasma, and reversal agents for newer anticoagulation agents are being developed. Surgical interventions are options fraught with complications, and are decided on a case-by-case basis. Our current state of understanding of this condition and its management is insufficient. This deficit calls for more population-based studies and therapeutic trials to better evaluate risk factors for, and to prevent and treat AICH
Metrizability of holonomy invariant projective deformation of sprays
In this paper, we consider projective deformation of the geodesic system of
Finsler spaces by holonomy invariant functions: Starting by a Finsler spray
and a holonomy invariant function , we investigate the metrizability
property of the projective deformation . We prove
that for any holonomy invariant nontrivial function and for almost every
value , such deformation is not Finsler metrizable. We identify
the cases where such deformation can lead to a metrizable spray: in these
cases, the holonomy invariant function is necessarily one of the principal
curvatures of the geodesic structure
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