High-fidelity projective read-out of a solid-state spin quantum register

Initialization and read-out of coupled quantum systems are essential ingredients for the implementation of quantum algorithms. Single-shot read-out of the state of a multi-quantum-bit (multi-qubit) register would allow direct investigation of quantum correlations (entanglement), and would give access to further key resources such as quantum error correction and deterministic quantum teleportation. Although spins in solids are attractive candidates for scalable quantum information processing, their single-shot detection has been achieved only for isolated qubits. Here we demonstrate the preparation and measurement of a multi-spin quantum register in a low-temperature solid-state system by implementing resonant optical excitation techniques originally developed in atomic physics. We achieve high-fidelity read-out of the electronic spin associated with a single nitrogen-vacancy centre in diamond, and use this read-out to project up to three nearby nuclear spin qubits onto a well-defined state. Conversely, we can distinguish the state of the nuclear spins in a single shot by mapping it onto, and subsequently measuring, the electronic spin. Finally, we show compatibility with qubit control: we demonstrate initialization, coherent manipulation and single-shot read-out in a single experiment on a two-qubit register, using techniques suitable for extension to larger registers. These results pave the way for a test of Bell's inequalities on solid-state spins and the implementation of measurement-based quantum information protocols.     

Palmitate-induced skeletal muscle insulin resistance does not require NF-κB activation

Palmitate activates the NF-κB pathway, and induces accumulation of lipid metabolites and insulin resistance in skeletal muscle cells. Little information is available whether and how these processes are causally related. Therefore, the objectives were to investigate whether intra-cellular lipid metabolites are involved in FA-induced NF-κB activation and/or insulin resistance in skeletal muscle and to investigate whether FA-induced insulin resistance and NF-κB activation are causally related. Inhibiting DGAT or CPT-1 by using, respectively, amidepsine or etomoxir increased DAG accumulation and sensitized myotubes to palmitate-induced insulin resistance. While co-incubation of palmitate with etomoxir increased NF-κB transactivation, co-incubation with amidepsine did not, indicating that DAG accumulation is associated with insulin resistance but not with NF-κB activation. Furthermore, pharmacological or genetic inhibition of the NF-κB pathway could not prevent palmitate-induced insulin resistance. In conclusion, we have demonstrated that activation of the NF-κB pathway is not required for palmitate-induced insulin resistance in skeletal muscle cells.     

A New Venture Analysis Method and Its Application

The new venture analysis is the foundation of venturedevelopment. In this paper, 14 venture prototypesare proposed based on the attributes of venture.Then, a new venture analysis method is discussed bythe wny of matching the new venture with thecorresponding prototype. Considering the fuzziness ofhuman subjective grading, the L-R fuzzy numbers are     

A quantum scattering interferometer

The collision of two ultracold atoms results in a quantum mechanical superposition of the two possible outcomes: each atom continues without scattering, and each atom scatters as an outgoing spherical wave with an s-wave phase shift. The magnitude of the s-wave phase shift depends very sensitively on the interaction between the atoms. Quantum scattering and the underlying phase shifts are vitally important in many areas of contemporary atomic physics, including Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic clocks and magnetically tuned Feshbach resonances. Precise experimental measurements of quantum scattering phase shifts have not been possible because the number of scattered atoms depends on the s-wave phase shifts as well as the atomic density, which cannot be measured precisely. Here we demonstrate a scattering experiment in which the quantum scattering phase shifts of individual atoms are detected using a novel atom interferometer. By performing an atomic clock measurement using only the scattered part of each atom's wavefunction, we precisely measure the difference of the s-wave phase shifts for the two clock states in a density-independent manner. Our method will enable direct and precise measurements of ultracold atom-atom interactions, and may be used to place stringent limits on the time variations of fundamental constants.     

约当重心定理的一个新证明

约当重心定理（１８６９年）提出，一棵树的重心不是由一个单一的顶点组成，就是由一对相邻的顶点组成－这篇文章提出了一个证明这个定理的新方法－     

Genetics of hybridization between the pocket gophers Thomomys bottae and Thomomys townsendii in northeastern California

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Terminal bud formation in limber pine

The progress of bud development was studied in limber pines growing in the mountains of northeastern Utah. Initiation of new bud scales began in mid-June, several weeks after elongation of the current shoot had begun. Needle primordia first appeared in September and continued to form through the winter, until all were present in May. This winter activity is believed to be fostered by surface temperatures on the terminal buds considerably higher than ambient air temperatures.     

A self-pollination experiment in Pinus edulis

Controlled pollinations were performed on four pinyons ( Pinus edulis Engelm.) to compare the results of selfing and outcrossing. Final cone size was the same under both treatments. There was no significant difference in number of seeds per cone. Filled-seed yields averaged 14.4 percent in selfings and 90.5 percent in outcrossings. Relative self-fertility averaged about 15 percent, a level comparable with that of other pine species studied.