Strategies to Restore Hearing

We discuss strategies within the field to restore hearing in the context of a flat epithelia model. This could assist in avoiding the limitations of current treatment options along with the obstacles associated with cellular restoration attempts. A review of the important genes required for the development, differentiation, and long-term maintenance of the organ of Corti (OC) demonstrates that any future direction to regenerate hair cells necessitates a better understanding of the gene expression in addition to the cells present during the phalangeal scarring process and the flat epithelia environment. This understanding could be achieved through the development of a characterized flat epithelia, followed by complete regeneration of various sensory cell types in the correct location that respond appropriately to noise stimuli. Of course, this strategy would have to be modified for the different types and cellular manifestations of hearing loss. The characterization of the flat epithelia model and the context of the genes can be further manipulated for precise regeneration of a functional OC based on the cellular environment within the specific patient’s cochlea

Maximally localized states and causality in non commutative quantum theories

We give simple representations for quantum theories in which the position commutators are non vanishing constants. A particular representation reproduces results found using the Moyal star product. The notion of exact localization being meaningless in these theories, we adapt the notion of ``maximally localized states'' developed in another context . We find that gaussian functions play this role in a 2+1 dimensional model in which the non commutation relations concern positions only. An interpretation of the wave function in this non commutative geometry is suggested. We also analyze higher dimensional cases. A possible incidence on the causality issue for a Q.F.T with a non commuting time is sketched.Comment: 11 pages, Revtex. The presentation has been improved, the subsection on high dimensions has been modified. This version will appear in PR

Hydrogen atom as an eigenvalue problem in 3D spaces of constant curvature and minimal length

An old result of A.F. Stevenson [Phys. Rev.} 59, 842 (1941)] concerning the Kepler-Coulomb quantum problem on the three-dimensional (3D) hypersphere is considered from the perspective of the radial Schr\"odinger equations on 3D spaces of any (either positive, zero or negative) constant curvature. Further to Stevenson, we show in detail how to get the hypergeometric wavefunction for the hydrogen atom case. Finally, we make a comparison between the ``space curvature" effects and minimal length effects for the hydrogen spectrumComment: 6 pages, v

Vacuum entanglement enhancement by a weak gravitational field

Separate regions in space are generally entangled, even in the vacuum state. It is known that this entanglement can be swapped to separated Unruh-DeWitt detectors, i.e., that the vacuum can serve as a source of entanglement. Here, we demonstrate that, in the presence of curvature, the amount of entanglement that Unruh-DeWitt detectors can extract from the vacuum can be increased.Comment: 6 pages, 1 figur

On the Space-Time Uncertainty Relations of Liouville Strings and D Branes

Within a Liouville approach to non-critical string theory, we argue for a non-trivial commutation relation between space and time observables, leading to a non-zero space-time uncertainty relation $\delta x \delta t > 0$, which vanishes in the limit of weak string coupling.Comment: 8 pages, LaTe

Unsharp Degrees of Freedom and the Generating of Symmetries

In quantum theory, real degrees of freedom are usually described by operators which are self-adjoint. There are, however, exceptions to the rule. This is because, in infinite dimensional Hilbert spaces, an operator is not necessarily self-adjoint even if its expectation values are real. Instead, the operator may be merely symmetric. Such operators are not diagonalizable - and as a consequence they describe real degrees of freedom which display a form of "unsharpness" or "fuzzyness". For example, there are indications that this type of operators could arise with the description of space-time at the string or at the Planck scale, where some form of unsharpness or fuzzyness has long been conjectured. A priori, however, a potential problem with merely symmetric operators is the fact that, unlike self-adjoint operators, they do not generate unitaries - at least not straightforwardly. Here, we show for a large class of these operators that they do generate unitaries in a well defined way, and that these operators even generate the entire unitary group of the Hilbert space. This shows that merely symmetric operators, in addition to describing unsharp physical entities, may indeed also play a r{\^o}le in the generation of symmetries, e.g. within a fundamental theory of quantum gravity.Comment: 23 pages, LaTe

Continuous deformations of the Grover walk preserving localization

The three-state Grover walk on a line exhibits the localization effect characterized by a non-vanishing probability of the particle to stay at the origin. We present two continuous deformations of the Grover walk which preserve its localization nature. The resulting quantum walks differ in the rate at which they spread through the lattice. The velocities of the left and right-traveling probability peaks are given by the maximum of the group velocity. We find the explicit form of peak velocities in dependence on the coin parameter. Our results show that localization of the quantum walk is not a singular property of an isolated coin operator but can be found for entire families of coins

Long thoracic nerve release for scapular winging: Clinical study of a continuous series of eight patients

SummaryScapular winging secondary to serratus anterior muscle palsy is a rare pathology. It is usually due to a lesion in the thoracic part of the long thoracic nerve following violent upper-limb stretching with compression on the nerve by the anterior branch of thoracodorsal artery at the “crow's foot landmark” where the artery crosses in front of the nerve. Scapular winging causes upper-limb pain, fatigability or impotence. Diagnosis is clinical and management initially conservative. When functional treatment by physiotherapy fails to bring recovery within 6months and electromyography (EMG) shows increased distal latencies, neurolysis may be suggested. Muscle transfer and scapula-thoracic arthrodesis are considered as palliative treatments. We report a single-surgeon experience of nine open neurolyses of the thoracic part of the long thoracic nerve in eight patients. At 6months’ follow-up, no patients showed continuing signs of winged scapula. Control EMG showed significant reduction in distal latency; Constant scores showed improvement, and VAS-assessed pain was considerably reduced. Neurolysis would thus seem to be the first-line surgical attitude of choice in case of compression confirmed on EMG. The present results would need to be confirmed in larger studies with longer follow-up, but this is made difficult by the rarity of this pathology.Level of evidenceIII