Automated Cloud Patch Segmentation of FY-2C Image Using Artificial Neural Network and Seeded Region Growing Method (ANN-SRG)

This paper presents a new algorithm Artificial Neural Network and Seeded Region Growing (ANN-SRG) to segment cloud patches of different types. This method used Seeded Region Growing (SRG) as segmentation algorithm, and Artificial Neural Network (ANN) Cloud classification as preprocessing algorithm. It can be trained to respond favorably to cloud types of interest, and SRG method is no longer sensitive to the seeds selection and growing rule. To illustrate the performance of this technique, this paper applied it on Chinese first operational geostationary meteorological satellite FengYun-2C (FY-2C) in three infrared channels (IR1, 10.3- 11.33BC;m; IR2, 11.5-12.53BC;m and WV 6.3-7.63BC;m) with 2864 samples collected by meteorologists in June, July, and August in 2007. The result shows that this method can distinguish and segment cloud patches of different types, and improves the traditional SRG algorithm by reducing the uncertainty of seeds extraction and regional growth

Single-photon transport and mechanical NOON state generation in microcavity optomechanics

We investigate the single-photon transport in a single-mode optical fiber coupled to an optomechanical system in the single-photon strong-coupling regime. The single-photon transmission amplitude is analytically obtained with a real-space approach and the effects of thermal noises are studied via master-equation simulations. The results provide an explicit understanding of optomechanical interaction and offer a useful guide for manipulating single photons in optomechanical systems. Based on the theoretical framework, we further propose a scheme to generate the mechanical NOON states with arbitrary phonon numbers by measuring the sideband photons. The probability for generating the NOON state with five phonons is over 0.15.Comment: 13 pages, 6 figure

Peripheral nerve injury and TRPV1-expressing primary afferent C-fibers cause opening of the blood-brain barrier

<p>Abstract</p> <p>Background</p> <p>The blood-brain barrier (BBB) plays the crucial role of limiting exposure of the central nervous system (CNS) to damaging molecules and cells. Dysfunction of the BBB is critical in a broad range of CNS disorders including neurodegeneration, inflammatory or traumatic injury to the CNS, and stroke. In peripheral tissues, the vascular-tissue permeability is normally greater than BBB permeability, but vascular leakage can be induced by efferent discharge activity in primary sensory neurons leading to plasma extravasation into the extravascular space. Whether discharge activity of sensory afferents entering the CNS may open the BBB or blood-spinal cord barrier (BSCB) remains an open question.</p> <p>Results</p> <p>Here we show that peripheral nerve injury (PNI) produced by either sciatic nerve constriction or transecting two of its main branches causes an increase in BSCB permeability, as assessed by using Evans Blue dye or horseradish peroxidase. The increase in BSCB permeability was not observed 6 hours after the PNI but was apparent 24 hours after the injury. The increase in BSCB permeability was transient, peaking about 24-48 hrs after PNI with BSCB integrity returning to normal levels by 7 days. The increase in BSCB permeability was prevented by administering the local anaesthetic lidocaine at the site of the nerve injury. BSCB permeability was also increased 24 hours after electrical stimulation of the sciatic nerve at intensity sufficient to activate C-fibers, but not when A-fibers only were activated. Likewise, BSCB permeability increased following application of capsaicin to the nerve. The increase in permeability caused by C-fiber stimulation or by PNI was not anatomically limited to the site of central termination of primary afferents from the sciatic nerve in the lumbar cord, but rather extended throughout the spinal cord and into the brain.</p> <p>Conclusions</p> <p>We have discovered that injury to a peripheral nerve and electrical stimulation of C-fibers each cause an increase in the permeability of the BSCB and the BBB. The increase in permeability is delayed in onset, peaks at about 24 hours and is dependent upon action potential propagation. As the increase is mimicked by applying capsaicin to the nerve, the most parsimonious explanation for our findings is that the increase in permeability is mediated by activation of TRPV1-expressing primary sensory neurons. Our findings may be relevant to the development of pain and neuroplastic changes in the CNS following nerve injury. In addition, our findings may provide the basis for developing methods to purposefully open the BBB when needed to increase brain penetration of therapeutic agents that might normally be excluded by an intact BBB.</p

Superradiant Solid in Cavity QED Coupled to a Lattice of Rydberg Gas

We study an optical cavity coupled to a lattice of Rydberg atoms, which can be represented by a generalized Dicke model. We show that the competition between the atomic interaction and atom-light coupling induces a rich phase diagram. A novel "superradiant solid" (SRS) phase is found, where both the superradiance and crystalline orders coexist. Different from the normal second order superradiance (SR) transition, here both the Solid-1/2 and SRS to SR phase transitions are first order. These results are confirmed by the large scale quantum Monte Carlo simulations.Comment: 5 pages,4 figure

Effective Photon-Photon Interactions in Largely Detuned Optomechanics

We propose to realize effective beam-splitter-like and two-mode-squeezing photon-photon interactions in a strong coupling optomechanical interface by exploiting detuned driving lasers. In this interface, the transitions between the optical system and the mechanical oscillator are suppressed by the large energy offsets, therefore protecting the photon-photon interactions from mechanical dissipations. Moreover, the destructive quantum interference between the eigenmodes of the interface is capable of further reducing the effects of initial mechanical thermal occupations. The interface can serve as a universal block for photon state engineering and hybrid quantum networks in high-temperature thermal bath and without the requirement of cooling the mechanical oscillator to the ground state.Comment: 12 pages, 4 figure