1,635 research outputs found

    Crustal structure between the Knipovich Ridge and the Van Mijenfjorden (Svalbard)

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    The Alfred Wegener Institute of Polar and Marine Research, the University of Bergenand the Hokkaido University acquired new seismic refraction data along a transect fromthe Knipovich Ridge to the inner Van Mijenfjorden in southern Svalbard. A close spacing ofon- and offshore receivers and a dense marine shot pattern provide the data for a high resolutionp-wave velocity model for geological interpretation. Additional new seismic reflection data(University of Bergen) yield structural information for a more reliable analysis.Crustal thickness along the Van Mijenfjorden is 33 to 34 km. Seismic velocities of 5.0 km/sare observed within the upper crustal section of the Tertiary Central Spitsbergen Basin.A Paleozoic sedimentary basin with a depth of 8 to 10 km is associated with the Nordfjorden Block.The seismic velocities are up to 6.0 km/s. Paleozoic sedimentary rocks are expected furtherto the west of the Hornsund Lineament since seismic velocities reveal a similar range here.West of the Bellsund the continental crust thins gradually over a 90 km wide rifted zone.The velocity structure within this section is very complex and comprises zones of decreasedvelocities below the West Spitsbergen Fold Belt (down to 20 km depth) and slightly elevatedvelocities (7.2 km/s) at the crust-mantle transition. The first structure is interpreted as intensivelyfractured rocks linked to post-Late Paleocene transpressive orogenic activity and subsequentlyaffected by transtension during break-up from Greenland. The faster deep-crustal velocities aresupposed to express magmatic intrusions of an unidentified origin. Melts could either be channelled by theSpitsbergen Shear Zone from more distant sources, or originate in magmatic interaction between the northern Knipovich Ridgeand the neighbouring young rifted crust.Oceanic crust each side of the Knipovich Ridge is thin (~3.5 km) and is characterised by theabsence of oceanic layer 3 (3.5/4.1 to 4.7 km/s). The oceanic section exhibits zones of verythin crust (~1 km) that are interpreted as fracture zones. Beneath these we observed decreasedmantle velocities (~7.3 km/s) indicating probable serpentinization of peridotites along thesefracture zones. Thickness variations further provide information about the segmentationand magma supply along the northern Knipovich Ridge

    Long-term memory in amnesia: Cued recall, recognition memory, and confidence ratings.

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    Scattering functions of knotted ring polymers

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    We discuss the scattering function of a Gaussian random polygon with N nodes under a given topological constraint through simulation. We obtain the Kratky plot of a Gaussian polygon of N=200 having a fixed knot for some different knots such as the trivial, trefoil and figure-eight knots. We find that some characteristic properties of the different Kratky plots are consistent with the distinct values of the mean square radius of gyration for Gaussian polygons with the different knots.Comment: 4pages, 3figures, 3table

    Experimental ancilla-assisted qubit transmission against correlated noise using quantum parity checking

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    We report the experimental demonstration of a transmission scheme of photonic qubits over unstabilized optical fibers, which has the plug-and-play feature as well as the ability to transmit any state of a qubit, regardless of whether it is known, unknown, or entangled to other systems. A high fidelity to the noiseless quantum channel was achieved by adding an ancilla photon after the signal photon within the correlation time of the fiber noise and by performing quantum parity checking. Simplicity, maintenance-free feature and robustness against path-length mismatches among the nodes make our scheme suitable for multi-user quantum communication networks.Comment: 8 pages, 4 figures; published in New J. Phys. and selected in IOP Selec

    Attenuation of ischemic liver injury by monoclonal anti-endothelin antibody, awETN40

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    Background: Enhanced production of endothelin-1 (ET1), vasoconstrictive 21 amino acids produced by endothelial cells during ischemia and after reperfusion of the liver, is known to cause sinusoidal constriction and microcirculatory disturbances, which lead to severe tissue damage. Using a 2- hour hepatic vascular exclusion model in dogs, we tested our hypothesis that neutralization of ET-1 by monoclonal anti-ET-1 and anti-ET-2 antibody (AwETN40) abates vascular dysfunction and ameliorates ischemia/reperfusion injury of the liver. Study Design: After skeletonization, the liver was made totally ischemic by cross-clamping the portal vein, the hepatic artery, and the vena cava (above and below the liver). Venovenous bypass was used to decompress splanchnic and inferior systemic congestion. AwETN40, 5 mg/kg, was administered intravenously 10 minutes before ischemia (treatment group, n = 5). Nontreated animals were used as controls (control group, n = 10). Animal survival, hepatic tissue blood flow, liver function tests; total bile acid, high-energy phosphate, ET-1 levels, and liver histopathology were studied. Results: Treatment with AwETN40 improved 2-week animal survival from 30% to 100%. Hepatic tissue blood flow after reperfusion was significantly higher in the treatment group. The treatment significantly attenuated liver enzyme release, total bile acid, and changes in adenine nucleotides. Immunoreactive ET-1 levels in the hepatic venous blood of the control group showed a significant increase and remained high for up to 24 hours after reperfusion. Histopathologic alterations were significantly lessened in the treatment group. Conclusions: These results indicate that ET-1 is involved in ischemia/reperfusion injury of the liver, which can be ameliorated by the monoclonal anti-ET-1 and antiET-2 antibody AwETN40

    Search for long-lived states in antiprotonic lithium

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    The spectrum of the (L_i^3 + p-bar + 2e) four-body system was calculated in an adiabatic approach. The two-electron energies were approximated by a sum of two single-electron effective charge two-center energies as suggested in [6]. While the structure of the spectrum does not exclude the existence of long-lived states, their experimental observability is still to be clarified

    Relaxation of a Single Knotted Ring Polymer

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    The relaxation of a single knotted ring polymer is studied by Brownian dynamics simulations. The relaxation rate lambda_q for the wave number q is estimated by the least square fit of the equilibrium time-displaced correlation function to a double exponential decay at long times. The relaxation rate distribution of a single ring polymer with the trefoil knot appears to behave as lambda_q=A(1/N^)x for q=1 and lambda_q=A'(q/N)^x' for q=2 and 3, where x=2.61, x'=2.02 and A>A'. The wave number q of the slowest relaxation rate for each N is given by q=2 for small values of N, while it is given by q=1 for large values of N. This crossover corresponds to the change of the structure of the ring polymer caused by the localization of the knotted part to a part of the ring polymer.Comment: 13 pages, 5 figures, uses jpsj2.cl

    Comparison between Serum and Saliva Biochemical Constituents in Dairy Cows during Lactation and Dry Period

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    The present study was undertaken to compare serum and salivary biochemical constituents during lactation and dry period in dairy cows. Also, the present study evaluated for the first time the salivary biochemical constituents in dairy cows. The study was carried out using 45 healthy multiparous Holstein cows maintained in dairy farms located in Morioka city (Iwate prefecture, Japan). Cows were classified into groups based on the month of lactation. Serum, saliva and milk samples were collected and analyzed. Data were statistically analyzed and the variation in serum and salivary biochemical constituents during lactation and dry period were discussed. From the present study, it could be concluded that the 1st month of lactation has the highest levels for serum free fatty acids (FFA), β- Hydroxy butyric acid (BHBA) and aceto Acetic acid (ACAC). The dry period has the highest serum glucose level and the lowest serum FFA, BHBA and aspartate aminotransferase levels. Both serum and salivary FFA showed the highest value during the 1st month of lactation. Saliva contains a high level of gamma glutamyl transferase. The level of ammonia in saliva is higher than its serum level during all months of lactation and dry period. Most of the biochemical constituents in saliva change in different way from serum during lactation and dry period. Milk protein/fat ratio of 0.7 may be not indicative for subclinical ketosis

    One-way quantum computing in a decoherence-free subspace

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    We introduce a novel scheme for one-way quantum computing (QC) based on the use of information encoded qubits in an effective cluster state resource. With the correct encoding structure, we show that it is possible to protect the entangled resource from phase damping decoherence, where the effective cluster state can be described as residing in a Decoherence-Free Subspace (DFS) of its supporting quantum system. One-way QC then requires either single or two-qubit adaptive measurements. As an example where this proposal can be realized, we describe an optical lattice setup where the scheme provides robust quantum information processing. We also outline how one can adapt the model to provide protection from other types of decoherence.Comment: 9 pages, 4 figures, RevTeX

    Average Structures of a Single Knotted Ring Polymer

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    Two types of average structures of a single knotted ring polymer are studied by Brownian dynamics simulations. For a ring polymer with N segments, its structure is represented by a 3N -dimensional conformation vector consisting of the Cartesian coordinates of the segment positions relative to the center of mass of the ring polymer. The average structure is given by the average conformation vector, which is self-consistently defined as the average of the conformation vectors obtained from a simulation each of which is rotated to minimize its distance from the average conformation vector. From each conformation vector sampled in a simulation, 2N conformation vectors are generated by changing the numbering of the segments. Among the 2N conformation vectors, the one closest to the average conformation vector is used for one type of the average structure. The other type of the averages structure uses all the conformation vectors generated from those sampled in a simulation. In thecase of the former average structure, the knotted part of the average structure is delocalized for small N and becomes localized as N is increased. In the case of the latter average structure, the average structure changes from a double loop structure for small N to a single loop structure for large N, which indicates the localization-delocalization transition of the knotted part.Comment: 15 pages, 19 figures, uses jpsj2.cl
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