The ice shelves in the Amundsen Sea are thinning rapidly, and the main reason for their decline appears to be warm ocean currents circulating below the ice shelves and melting these from below. Ocean currents transport warm dense water onto the shelf, channeled by bathymetric troughs leading to the deep inner basins. A hydrographic mooring equipped with an upward-looking ADCP has been placed in one of these troughs on the central Amundsen shelf. The two years (2010/11) of mooring data are here used to characterize the inflow of warm deep water to the deep shelf basins. During both years, the warm layer thickness and temperature peaked in austral fall. The along-trough velocity is dominated by strong fluctuations that do not vary in the vertical. These fluctuations are correlated with the local wind, with eastward wind over the shelf and shelf break giving flow toward the ice shelves. In addition, there is a persistent flow of dense lower Circumpolar Deep Water (CDW) toward the ice shelves in the bottom layer. This bottom-intensified flow appears to be driven by buoyancy forces rather than the shelfbreak wind. The years of 2010 and 2011 were characterized by a comparatively stationary Amundsen Sea low, and hence there were no strong eastward winds during winter that could drive an upwelling of warm water along the shelf break. Regardless of this, there was a persistent flow of lower CDW in the bottom layer during the two years. The average heat transport toward the ice shelves in the trough was estimated from the mooring data to be 0.95 TW.

This study was designed to isolate and identify a potent inhibitory compound against nitric oxide (NO) production from the stem bark of Ulmus pumila L. Ethyl acetate fraction of hot water extract registered a higher level of total phenolics (756.93 mg GAE/g) and also showed strong DPPH (IC50 at 5.6 μg/mL) and ABTS (TEAC value 0.9703) radical scavenging activities than other fractions. Crude extract and its fractions significantly decreased nitrite accumulation in LPS-stimulated RAW 264.7 cells indicating that they potentially inhibited the NO production in a concentration dependent manner. Based on higher inhibitory activity, the ethyl acetate fraction was subjected to Sephadex LH-20 column chromatography and yielded seven fractions and all these fractions registered appreciable levels of inhibitory activity on NO production. The most effective fraction F1 was further purified and subjected to (1)H, (13)C-NMR and mass spectrometry analysis and the compound was identified as icariside E4. The results suggest that the U. pumila extract and the isolated compound icariside E4 effectively inhibited the NO production and may be useful in preventing inflammatory diseases mediated by excessive production of NO.

One-step, laser-induced self-generation of nanoporous hybrid electrodes enables facile fabrication of high-performance and flexible micro-supercapacitors.

A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum-state tomography. We theoretically propose and experimentally demonstrate a general framework to manifest nonclassicality by observing a single marginal distribution only, which provides a unique insight into nonclassicality and a practical applicability to various quantum systems. Our approach maps the 1D marginal distribution into a factorized 2D distribution by multiplying the measured distribution or the vacuum-state distribution along an orthogonal axis. The resulting fictitious Wigner function becomes unphysical only for a nonclassical state; thus the negativity of the corresponding density operator provides evidence of nonclassicality. Furthermore, the negativity measured this way yields a lower bound for entanglement potential-a measure of entanglement generated using a nonclassical state with a beam-splitter setting that is a prototypical model to produce continuous-variable (CV) entangled states. Our approach detects both Gaussian and non-Gaussian nonclassical states in a reliable and efficient manner. Remarkably, it works regardless of measurement axis for all non-Gaussian states in finite-dimensional Fock space of any size, also extending to infinite-dimensional states of experimental relevance for CV quantum informatics. We experimentally illustrate the power of our criterion for motional states of a trapped ion, confirming their nonclassicality in a measurementaxis-independent manner. We also address an extension of our approach combined with phase-shift operations, which leads to a stronger test of nonclassicality, that is, detection of genuine nonGaussianity under a CV measurement.N onclassicality is a fundamentally profound concept to identify quantum phenomena inaccessible from classical physics. It also provides a practically useful resource, for example, entanglement, making possible a lot of applications in quantum information processing beyond classical counterparts (1-3). A wide range of quantum systems, for example, field amplitudes of light, collective spins of atomic ensembles, motional modes of trapped ions, and Bose-Einstein condensate and mechanical oscillators, can be used for quantum information processing based on continuous variables (CVs) (2). It is of crucial importance to establish efficient and reliable criteria of nonclassicality for CV systems, desirably testable with fewer experimental resources, for example, fewer measurement settings (4-8) and with the capability of detecting a broad class of nonclassical states. In this paper, in view of the Glauber-Sudarshan P function (9, 10), those states that cannot be represented as a convex mixture of coherent states are referred to as nonclassical.A standard method to obtain information on a CV quantum state is to measure marginal distributions along many different axes in phase space constituting quantum-state tomography (11).This tomographic reconstruction may r...

We theoretically propose and experimentally demonstrate a nonclassicality test of single-mode field in phase space, which has an analogy with the nonlocality test proposed by Wódkiewicz [Phys. Rev. Lett. 82, 2009 (1999)]. Our approach to deriving the classical bound draws on the fact that the Wigner function of a coherent state is a product of two independent distributions as if the orthogonal quadratures (position and momentum) in phase space behave as local realistic variables. Our method detects every pure nonclassical Gaussian state, which can also be extended to mixed states. Furthermore, it sets a bound for all Gaussian states and their mixtures, thereby providing a criterion to detect a genuine quantum non-Gaussian state. Remarkably, our phase-space approach with invariance under Gaussian unitary operations leads to an optimized test for a given non-Gaussian state. We experimentally show how this enhanced method can manifest quantum non-Gaussianity of a state by simply choosing phase-space points appropriately, which is essentially equivalent to implementing a squeezing operation on a given state.PACS numbers: 03.65. Ta, 42.50.Dv, 42.50.Ar Introduction-Nonclassicality of a quantum state is a topic of crucial importance that has attracted a lot of theoretical and experimental efforts for long. It provides not only a profound conceptual framework to distinguish quantum phenomena from classical ones, but also an essential practical basis for numerous applications, e.g. in quantum information processing. An important approach to studying quantum mechanics in comparison with classical mechanics is to adopt a phase-space description of a quantum state [1]. A wide variety of quantum systems of continuous variables (CVs) can be addressed in phase space, including quadrature amplitudes of light fields, collective spin states of atomic ensembles, and motional states of trapped ions, Bose-Einstein condensate, or mechanical oscillators, etc. [2]. Investigating quantum dynamics in phase space has yielded a great deal of intuition to quantum-to-classical transition [3]. It also offers a powerful tool to treat problems in quantum optics [4] and CV quantum informatics [5].A clear signature of nonclassicality is the negativity of phase-space distribution, which does not exist in classical probability distributions. However, its demonstration typically requires a full reconstruction of Wigner function [6] and it is of fundamental and practical significance to have a simpler set of measurements manifesting nonclassicality [7,8], desirably even when the Wigner function is non-negative. For instance, every Gaussian state possesses a positive-definite Wigner function, which restricts a possible set of nonclassicality tests. To manifest the Bell nonlocality, e.g., by employing homodyne detections, a Gaussian state must be transformed to a non-Gaussian state having a non-positive Wigner function to rule out hidden-variable models [9,10]. Banaszek and Wódkiewicz (BW) introduced a different seminal approach to manifesting CV ...