Enhanced multipartite quantum correlations by non-Gaussian operations

We study how conditional photon operations can affect multipartite quantum correlations, specifically nonlocality and entanglement, of the continuous variable GHZ states. We find that the violation of the Mermin-Klyshko inequality revealing the multipartite nonlocality can be made stronger with photon subtraction applied on each mode of the original GHZ states, particularly in a weak squeezing regime. Photon addition applied on local modes also turns out to enhance the degree of multipartite nonlocality in a broad range of parameters. We further investigate the effects of the photon operations on the degree of multipartite entanglement by looking into the Gaussian tangle, the fidelity of teleportation network, and the quadrature correlations. We find that photon subtraction applied on two modes enhances those entanglement characteristics in a practical squeezing regime while there is no improvement made by photon addition.Comment: 11 pages, 10 figures, to appear in Phys. Rev.

Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition

We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the EPR-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction and the addition particularly in the small squeezing regime, whereas the optimal operation becomes the photon subtraction in the large-squeezing regime.Comment: 6 pages, 6 figures, published versio

PERSPECTIVES OF WATER QUALITY IMPROVEMENT BY AQUATIC MACROPHYTES AS NUTRIENT SINK IN THE LAKE PALDANGHO, KOREA

Improvement of water quality by aquatic macrophytes was studied at the Lake Paldangho, a reservoir supplying the service water for 15 million inhabitants in the Capital of Korea. Annual production of aboveground of emergent plants having 1800 g DW/m² for Typha angustata and 1700g DW/m² for Zizania latifolia, are 15- to 30-folds as large as those of submersed plants having 110 g DW/m² for Ceratophyllum demersum and 60 g DW/m² for Hydrilla verticillata. Although concentrations of nitrogen and phosphorus in mg per g dry matter of emergent plants are small as a half of those of submersed ones, standing nutrients in g per m² of the former are 8- to 9-folds as large as that of the latter because of large production. Annual return of nutrients from the litters are also more in emergent plants than in submersed one. In the whole Lake the uptake amounts by macrophyte (sink) are 30.3 ton of nitrogen and 4.9 ton of phosphorus, and the return amounts from the litter (source) are 18.5 ton of nitrogen and 4.3 ton of phosphorus. Difference between the sink and the source, 11.8 ton for nitrogen and 0.6 ton for phosphorus, will remain in sediment of littoral zone. If aboveground of macrohytes are weeded out on time occurring the maximum production nutrients remaining will be reduced. To increase the annual production, repetitive harvesting of Zizania latifolia is effective.Article信州大学理学部付属諏訪臨湖実験所報告 7: 167-175(1991)departmental bulletin pape

Dispersion of Vascular Plant in An-do, Korea

AbstractThe vascular plants observed in the area were composed of a total of 342 taxa; 104 families, 239 genus, 309 species, 30 varieties, 2 forms and 1 sub-species. The endangered species found in the area were Glehnia littoralis Fr. Schm. and Milletia japonica (Siebold & Zucc.) A.Gray. The five endemic plants were found growing in the area like Carpinus coreana Nakai., Celtis choseniana Nakai, Clematis trichotoma, Spiraea prunifolia for. simpliciflora and Weigela subsessilis L.H.Bailey. Specialized plants of Geumodo were a total of 45 species; 34 taxa in Grade I, 10 taxa in Grade III, and 1 taxon in Grade V. Glehnia littoralis Fr. Schm. and Milletia japonica (Siebold & Zucc.) A.Gray confirmed in this study formed a colony alongside the coast and mountain paths. Currently, the construction to build water supply and sewer systems destroyed part of the colony. Therefore, in the long-term perspective, the conservation plan such as comprehensive research and monitoring on the ecosystem shall be established to protect indeciduous plants in the warm temperate zone

Hydraulic Strategy of Cactus Trichome for Absorption and Storage of Water under Arid Environment

Being an essential component in various metabolic activities, water is important for the survival of plants and animals. Cacti grown in arid areas have developed intrinsic water management systems, such as water collection through spines, water absorption through trichome, and water storage using mucilage. The water collection method of cactus is well-documented, but its water absorption and storage strategies remain to be elucidated. Thus, this study analyzed the morphology and wettability of cactus trichomes by using advanced bio-imaging techniques and by performing in vitro experiments on an artificial system mimicking these structures, respectively. In addition, the in situ water absorption process through the trichome cluster was quantitatively visualized. This paper proposes a new bio-inspired technique for dew collection based on information about the water management strategies of cactus. This study discusses the underlying water absorption and storage strategies of cactus and provides the experimental database required to develop a biomimetic water management device.114Ysciescopu

Ultraviolet photodepletion spectroscopy of dibenzo-18-crown-6-ether complexes with alkali metal cations

Ultraviolet photodepletion spectra of dibenzo-18-crown-6-ether complexes with alkali metal cations (M+-DB18C6, M = Cs, Rb, K, Na, and Li) were obtained in the gas phase using electrospray ionization quadrupole ion-trap reflectron time-of-flight mass spectrometry. The spectra exhibited a few distinct absorption bands in the wavenumber region of 35450−37800 cm^(−1). The lowest-energy band was tentatively assigned to be the origin of the S_0-S_1 transition, and the second band to a vibronic transition arising from the “benzene breathing” mode in conjunction with symmetric or asymmetric stretching vibration of the bonds between the metal cation and the oxygen atoms in DB18C6. The red shifts of the origin bands were observed in the spectra as the size of the metal cation in M^+-DB18C6 increased from Li^+ to Cs^+. We suggested that these red shifts arose mainly from the decrease in the binding energies of larger-sized metal cations to DB18C6 at the electronic ground state. These size effects of the metal cations on the geometric and electronic structures, and the binding properties of the complexes at the S_0 and S_1 states were further elucidated by theoretical calculations using density functional and time-dependent density functional theories

Insight into highly conserved H1 subtype-specific epitopes in influenza virus hemagglutinin

Influenza viruses continuously undergo antigenic changes with gradual accumulation of mutations in hemagglutinin (HA) that is a major determinant in subtype specificity. The identification of conserved epitopes within specific HA subtypes gives an important clue for developing new vaccines and diagnostics. We produced and characterized nine monoclonal antibodies that showed significant neutralizing activities against H1 subtype influenza viruses, and determined the complex structure of HA derived from a 2009 pandemic virus A/Korea/01/2009 (KR01) and the Fab fragment from H1-specific monoclonal antibody GC0587. The overall structure of the complex was essentially identical to the previously determined KR01 HA-Fab0757 complex structure. Both Fab0587 and Fab0757 recognize readily accessible head regions of HA, revealing broadly shared and conserved antigenic determinants among H1 subtypes. The beta-strands constituted by Ser110-Glu115 and Lys169-Lys170 form H1 epitopes with distinct conformations from those of H1 and H3 HA sites. In particular, Glu112, Glu115, Lys169, and Lys171 that are highly conserved among H1 subtype HAs have close contacts with HCDR3 and LCDR3. The differences between Fab0587 and Fab0757 complexes reside mainly in HCDR3 and LCDR3, providing distinct antigenic determinants specific for 1918 pdm influenza strain. Our results demonstrate a potential key neutralizing epitope important for H1 subtype specificity in influenza virus