1,097 research outputs found
Loop quantum effect and the fate of tachyon field collapse
We study the fate of gravitational collapse of a tachyon field matter. In
presence of an inverse square potential a black hole forms. Loop quantum
corrections lead to the avoidance of classical singularities, which is followed
by an outward flux of energy.Comment: Contribution to the conference of Loops'11, Madri
Advanced Strategies for the Regeneration of Lumbar Disc Annulus Fibrosus.
Damage to the annulus fibrosus (AF), the outer region of the intervertebral disc (IVD), results in an undesirable condition that may accelerate IVD degeneration causing low back pain. Despite intense research interest, attempts to regenerate the IVD have failed so far and no effective strategy has translated into a successful clinical outcome. Of particular significance, the failure of strategies to repair the AF has been a major drawback in the regeneration of IVD and nucleus replacement. It is unlikely to secure regenerative mediators (cells, genes, and biomolecules) and artificial nucleus materials after injection with an unsealed AF, as IVD is exposed to significant load and large deformation during daily activities. The AF defects strongly change the mechanical properties of the IVD and activate catabolic routes that are responsible for accelerating IVD degeneration. Therefore, there is a strong need to develop effective therapeutic strategies to prevent or reconstruct AF damage to support operational IVD regenerative strategies and nucleus replacement. By the way of this review, repair and regenerative strategies for AF reconstruction, their current status, challenges ahead, and future outlooks were discussed
Tuning Surface Morphology of Fluorescent Hydrogels Using a Vortex Fluidic Device.
In recent decades, microfluidic techniques have been extensively used to advance hydrogel design and control the architectural features on the micro- and nanoscale. The major challenges with the microfluidic approach are clogging and limited architectural features: notably, the creation of the sphere, core-shell, and fibers. Implementation of batch production is almost impossible with the relatively lengthy time of production, which is another disadvantage. This minireview aims to introduce a new microfluidic platform, a vortex fluidic device (VFD), for one-step fabrication of hydrogels with different architectural features and properties. The application of a VFD in the fabrication of physically crosslinked hydrogels with different surface morphologies, the creation of fluorescent hydrogels with excellent photostability and fluorescence properties, and tuning of the structure-property relationship in hydrogels are discussed. We conceive, on the basis of this minireview, that future studies will provide new opportunities to develop hydrogel nanocomposites with superior properties for different biomedical and engineering applications
Underwriting relationships and analyst independence in Europe.
This paper examines the accuracy of security analysts' earnings forecasts and stock recommendations for firms in 13 European countries. We document at least three key findings. First, we find strong evidence that lead and co-lead underwriter analysts' earnings estimates and stock recommendations are significantly more optimistic than those provided by unaffiliated analysts. Second, we find that lead and co-lead underwriter analysts' earnings forecast and stock recommendations are significantly more optimistic for underwriter stocks than for those they provide for other stocks. Third, we also find evidence that these biases found within earnings forecasts and stock recommendations are not driven by one particular country. In short, these findings suggest that affiliated analysts are more optimistic perhaps to maintain investment banking relations
Classical Cost of Transmitting a Qubit
We consider general prepare-and-measure scenarios in which Alice can transmit
qubit states to Bob, who can perform general measurements in the form of
positive operator-valued measures (POVMs). We show that the statistics obtained
in any such quantum protocol can be simulated by the purely classical means of
shared randomness and two bits of communication. Furthermore, we prove that two
bits of communication is the minimal cost of a perfect classical simulation. In
addition, we apply our methods to Bell scenarios, which extends the well-known
Toner and Bacon protocol. In particular, two bits of communication are enough
to simulate all quantum correlations associated to arbitrary local POVMs
applied to any entangled two-qubit state.Comment: 4 pages main text, 10 pages appendix, matches published versio
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