Robust Spin Squeezing Preservation in Photonic Crystal Cavities

We show that the robust spin squeezing preservation can be achieved by utilizing detuning modification for an ensemble of N separate two-level atoms embedded in photonic crystal cavities (PCC). In particular, we explore the different dynamical behaviors of spin squeezing between isotropic and anisotropic PCC cases when the atomic frequency is inside the band gap. In both cases, it is shown that the robust preservation of spin squeezing is completely determined by the formation of bound states. Intriguingly, we find that unlike the isotropic case where steady-state spin squeezing varies smoothly when the atomic frequency moves from the inside to the outside band edge, a sudden transition occurs for the anisotropic case. The present results may be of direct importance for, e.g., quantum metrology in open quantum systems.Comment: 6 pages, 4 figures, accepted by Laser Physics Letter

Enhancing teleportation of quantum Fisher information by partial measurements

The purport of quantum teleportation is to completely transfer information from one party to another distant partner. However, from the perspective of parameter estimation, it is the information carried by a particular parameter, not the information of total quantum state that needs to be teleported. Due to the inevitable noise in environment, we propose two schemes to enhance quantum Fisher information (QFI) teleportation under amplitude damping noise with the technique of partial measurements. We find that post partial measurement can greatly enhance the teleported QFI, while the combination of prior partial measurement and post partial measurement reversal could completely eliminate the effect of decoherence. We show that, somewhat consequentially, enhancing QFI teleportation is more economic than that of improving fidelity teleportation. Our work extends the ability of partial measurements as a quantum technique to battle decoherence in quantum information processing.Comment: Revised version, minor changes, accepted by Phys. Rev.

3′,6′-Bis(diethyl­amino)-2-(2-hydroxy­ethyl­amino)spiro­[isoindoline-1,9′-xanthen]-3-one

In the title mol­ecule, C30H36N4O3, the dihedral angle between the planes of the xanthene and spiro­lactam rings systems is 88.69 (4)°. Both C atoms of one of the ethyl groups are disordered over two sites with occupancies 0.72 (2)/0.28 (2). The conformation of the mol­ecule may be influenced by two intra­molecular hydrogen bonds

1-[1-(Hydroxy­imino)eth­yl]-N-(2-methoxy­phen­yl)cyclo­propane­carboxamide

The title compound, C13H16N2O3, adopts an E configuration with respect to the C=N bond and an intra­molecular N—H⋯N hydrogen bond results in the formation of a six-membered ring. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into a chain propagating along the b axis. Very weak π–π stacking inter­actions [centroid–centroid distance = 4.18 (2) Å] may further consolidate the packing, forming a two-dimensional supra­molecular network

Poly[[{μ3-dihydrogen [(pyridin-4-yl­methyl­imino)­bis­(methyl­ene)]diphos­phon­ato-κ5 O:O′,N,O′′:N′}copper(II)] dihydrate]

In the title polymer, {[Cu(C8H12N2O6P2)]·2H2O}n, the geometry of the five-coordinate CuII ion can best be described as slightly distorted square-pyramidal formed by one N and two O atoms of an N(CH2PO3H)2 group and one N atom from a pyridine ring. The elongated apex of the pyramid is occupied by one O atom from a third diphospho­nate ligand. The inter­connection of Cu2+ ions by the diphospho­nate ligands results in the formation of a double-chain array along the b axis, in which the two sub-chains are inter­locked by pairs of PO3 groups. The outside of each sub-chain is decorated by other PO3 groups. These double chains are further assembled into a three-dimensional supra­molecular architecture via a large number of O—H⋯O hydrogen bonds between the phospho­nate groups and lattice water mol­ecules

Cognition contra camouflage: How the brain mediates predator-driven crypsis evolution

While crypsis is a prominent antipredator adaptation, the role of the brain in predator-driven evolution remains controversial. Resolving this controversy requires contextualizing the brain with established antipredator traits and predation pressure. We hypothesize that the reduced predation risk through crypsis relaxes predation-driven selection on the brain and provide comparative evidence across 102 Chinese frog species for our hypothesis. Specifically, our phylogenetic path analysis reveals an indirect relationship between predation risk and crypsis that is mediated by brain size. This result suggests that at a low predation risk, frogs can afford to be conspicuous and use their large brain for cognitive predator evasion. This strategy may become less efficient or energetically costlier under higher predation pressure, favoring smaller brains and instead increasing crypsis

Plasma Lipoprotein-associated Phospholipase A2 in Patients with Metabolic Syndrome and Carotid Atherosclerosis

<p>Abstract</p> <p>Background</p> <p>Lipoprotein-associated phospholipase A₂(Lp-PLA₂) is a recently identified and potentially useful plasma biomarker for cardiovascular and atherosclerotic diseases. However, the correlation between the Lp-PLA₂activity and carotid atherosclerosis remains poorly investigated in patients with metabolic syndrome (MetS). The present study aimed to evaluate the potential role of Lp-PLA₂as a comprehensive marker of metabolic syndrome in individuals with and without carotid atherosclerosis.</p> <p>Methods</p> <p>We documented 118 consecutive patients with MetS and 70 age- and sex-matched healthy subjects served as controls. The patients were further divided into two groups: 39 with carotid plaques and 79 without carotid plaques to elucidate the influence of Lp-PLA₂on carotid atherosclerosis. The plasma Lp-PLA₂activity was measured by using ELISA method and carotid intimal-media thickness (IMT) was performed by ultrasound in all participants.</p> <p>Results</p> <p>Lp-PLA₂activity was significantly increased in MetS subgroups when compared with controls, and was higher in patients with carotid plaques than those without plaques (<it>P </it>< 0.05). Furthermore, we found that significant difference in Lp-PLA₂was obtained between patients with three and four disorders of metabolic syndrome (<it>P </it>< 0.01). Age (β = 0.183, <it>P </it>= 0.029), LDL-cholesterol (β = 0.401, <it>P </it>= 0.000) and waist-hip ratio (β = 0.410, <it>P </it>= 0.000) emerged as significant and independent determinants of Lp-PLA₂activity. Multiple stepwise regression analysis revealed that LDL-cholesterol (β = 0.309, <it>P </it>= 0.000), systolic blood pressure (β = 0.322, <it>P </it>= 0.002) and age (β = 0.235, <it>P </it>= 0.007) significantly correlated with max IMT, and Lp-PLA₂was not an independent predictor for carotid IMT.</p> <p>Conclusions</p> <p>Lp-PLA₂may be a modulating factor for carotid IMT via age and LDL-cholesterol, not independent predictor in the pathophysiological process of carotid atherosclerosis in patients with MetS.</p