Search results for " Spin"
showing 10 items of 1036 documents
Heat-induced action potential discharges in nociceptive primary sensory neurons of rats.
2009
Although several transducer molecules for noxious stimuli have been identified, little is known about the transformation of the resulting generator currents into action potentials (APs). Therefore we investigated the transformation process for stepped noxious heat stimuli (42-47 degrees C, 3-s duration) into membrane potential changes and subsequent AP discharges using the somata of acutely dissociated small dorsal root ganglion (DRG) neurons (diameteror=32.5 microm) of adult rats as a model for their own peripheral terminals. Three types of heat-induced membrane potential changes were differentiated: type 1, heat-induced AP discharges (approximately 37% of the neurons); type 2, heat-induce…
Heavy quark spin symmetry and SU(3)-flavour partners of the X (3872)
2013
In this work, an Effective Field Theory (EFT) incorporating light SU(3)-flavour and heavy quark spin symmetries is used to describe charmed meson-antimeson bound states. At Lowest Order (LO), this means that only contact range interactions among the heavy meson and antimeson fields are involved. Besides, the isospin violating decays of the X(3872) will be used to constrain the interaction between the D and a (D) over bar* mesons in the isovector channel. Finally, assuming that the X(3915) and Y(4140) resonances are D* (D) over bar* and D-s* (D) over bar (s)* molecular states, we can determine the four Low Energy Constants (LECs) of the EFT that appear at LO and, therefore, the full spectrum…
The Capparis spinosa L. group (Capparaceae) in Australia
2003
Summary The Australian form of the Capparis spinosa group, at present treated as var. nummularia (DC.) Bailey, has been studied through field and herbarium investigations. Cultivations away from the distribution range were also carried out to test the maintenance of diagnostic characters in this taxon. Based on the obtained data, coupled with phytogeographical considerations and comparisons with the variants widespread in other areas, for the Australian form the subspecific rank is here proposed. Its distribution and autecology are also discussed.
Carrier screening for spinal muscular atrophy in Italian population
2014
Spinal muscular atrophy (SMA) is an autosomal-recessive neuromuscular disorder characterized by motor neuron degeneration in the anterior horn of the spinal cord and brain stem, resulting in progressive muscle weakness and atrophy. The responsible survival motor neuron gene (SMN1; HGNC: 11117) is localized in 5q11.2-13.3. Screening for carriers of SMA is necessary for effective clinical/prenatal diagnosis and genetic counselling. In this study, the copy number of SMN1 gene was determined from a southern Italian population to estimate carrier frequency. This is the first report addressing the estimation of SMA carrier frequency in an Italian population. Our results show that the SMA carrier …
Cubic interactions of Maxwell-like higher spins
2017
We study the cubic vertices for Maxwell-like higher-spins in flat and (A)dS background spaces of any dimension. Reducibility of their free spectra implies that a single cubic vertex involving any three fields subsumes a number of couplings among different particles of various spins. The resulting vertices do not involve traces of the fields and in this sense are simpler than their Fronsdal counterparts. We propose an extension of both the free theory and of its cubic deformation to a more general class of partially reducible systems, that one can obtain from the original theory upon imposing trace constraints of various orders. The key to our results is a version of the Noether procedure al…
The geometry of N=3 AdS4 in massive IIA
2018
The geometry of the ${\cal N} = 3$, SO(4)--invariant, AdS$_4$ solution of massive type IIA supergravity that uplifts from the ${\cal N} = 3 $ vacuum of $D=4$ ${\cal N} = 8$ dyonic ISO(7) supergravity is investigated. Firstly, a $D=4$, SO(4)--invariant restricted duality hierarchy is constructed and used to uplift the entire, dynamical SO(4)--invariant sector to massive type IIA. The resulting consistent uplift formulae are used to obtain a new local expression for the ${\cal N} = 3 $ AdS$_4$ solution in massive IIA and analyse its geometry. Locally, the internal $S^6$ geometry corresponds to a warped fibration of $S^2$ and a hemisphere of $S^4$. This can be regarded as a warped generalisati…
Spinor moving frame, M0-brane covariant BRST quantization and intrinsic complexity of the pure spinor approach
2007
To exhibit the possible origin of the inner complexity of the Berkovits's pure spinor approach, we consider the covariant BRST quantization of the D=11 massless superparticle (M0-brane) in its spinor moving frame or twistor-like Lorentz harmonics formulation. The presence of additional twistor-like variables (spinor harmonics) allows us to separate covariantly the first and the second class constraints. After taking into account the second class constraints by means of Dirac brackets and after further reducing the first class constraints algebra, the dynamical system is described by the cohomology of a simple BRST charge associated to the d=1, n=16 supersymmetry algebra. The calculation of …
D=11massless superparticle covariant quantization, pure spinor BRST charge and hidden symmetries
2007
We consider the covariant quantization of the D=11 massless superparticle (M0-brane) in the spinor moving frame or twistor-like Lorentz harmonics formulation. The action involves the set of 16 constrained 32 component Majorana spinors, the spinor Lorentz harmonics parametrizing (as homogeneous coordinates, modulo gauge symmetries) the celestial sphere S9. There presence allows us to separate covariantly the first and the second class constraints of the model. After taking into account the second class constraints by means of Dirac brackets and after further reducing the first class constraints algebra, the system is described in terms of a simple BRST charge associated to the d=1, n=16 supe…
Quantum geometry and microscopic black hole entropy
2006
9 pages, 6 figures.-- PACS nrs.: 04.60.Pp, 04.70.Dy.-- ISI Article Identifier: 000242448900013.-- Published online on Nov 28, 2006.
Confinement-deconfinement transition due to spontaneous symmetry breaking in quantum Hall bilayers
2015
Band-inverted electron-hole bilayers support quantum spin Hall insulator and exciton condensate phases. We investigate such a bilayer in an external magnetic field. We show that the interlayer correlations lead to formation of a helical quantum Hall exciton condensate state. In contrast to the chiral edge states of the quantum Hall exciton condensate in electron-electron bilayers, existence of the counterpropagating edge modes results in formation of a ground state spin-texture not supporting gapless single-particle excitations. This feature has deep consequences for the low energy behavior of the system. Namely, the charged edge excitations in a sufficiently narrow Hall bar are confined, i…