Gain-Bandwith Product of Power Grid Tubes and Application to AGS Power Amplifier Driver

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Cross-verification of independent quantum devices

Quantum computers are on the brink of surpassing the capabilities of even the most powerful classical computers. This naturally raises the question of how one can trust the results of a quantum computer when they cannot be compared to classical simulation. Here we present a verification technique that exploits the principles of measurement-based quantum computation to link quantum circuits of different input size, depth, and structure. Our approach enables consistency checks of quantum computations within a device, as well as between independent devices. We showcase our protocol by applying it to five state-of-the-art quantum processors, based on four distinct physical architectures: nuclear magnetic resonance, superconducting circuits, trapped ions, and photonics, with up to 6 qubits and 200 distinct circuits

Conformational Dependence of a Protein Kinase Phosphate Transfer Reaction

Atomic motions and energetics for a phosphate transfer reaction catalyzed by the cAMP-dependent protein kinase (PKA) are calculated by plane-wave density functional theory, starting from structures of proteins crystallized in both the reactant conformation (RC) and the transition-state conformation (TC). In the TC, we calculate that the reactants and products are nearly isoenergetic with a 0.2 eV barrier; while phosphate transfer is unfavorable by over 1.2 eV in the RC, with an even higher barrier. With the protein in the TC, the motions involved in reaction are small, with only P$_\gamma$ and the catalytic proton moving more than 0.5 \AA. Examination of the structures reveals that in the RC the active site cleft is not completely closed and there is insufficient space for the phosphorylated serine residue in the product state. Together, these observations imply that the phosphate transfer reaction occurs rapidly and reversibly in a particular conformation of the protein, and that the reaction can be gated by changes of a few tenths of an \AA in the catalytic site.Comment: revtex4, 7 pages, 4 figures, to be submitted to Scienc

Not entirely displacement: conceptualizing relocation in Ethiopia and South Africa as “disruptive re-placement”

Residents’ lived experiences of movement into state directed housing frequently evidence contradictory outcomes. Often, movement is articulated in terms of displacement, noting its profoundly negative outcomes. However, displacement does not always fully capture contradictions, particularly where housing programmes form part of wider developmental strategies, themselves ambiguous in practice. Adopting a relational analysis, the paper argues for consideration of new sites of settlement relative to previous locations through a critical evaluation of place, as well as accounting for dynamism of urban change over time. Framings must capture residents varied and contradictory lived experiences and the relationality of place experiences. Contributing to work in this field, this paper calls for a broader analytical framing, named here as “disruptive re-placement”. Drawing on two different housing programmes, in South Africa and Ethiopia the paper charts movement into, and living in, state-led housing in three case study areas within three cities. It employs a ‘lived experiences’ methodology to understand these relocations, drawing on residents’ accounts of disruptive re-placement to examine the materialities of planned state-provided formal housing; the spatialities of disruptive re-placement; the economic and socio-political dimensions of these processes and the significance of temporality in shaping disruption. A continuum of disruptive and injurious re-placement, and a critique of the developmental state is used to articulate a just urban agenda in relation to relocation practices

Optical absorption spectra in fullerenes C60 and C70: Effects of Coulomb interactions, lattice fluctuations, and anisotropy

Effects of Coulomb interactions and lattice fluctuations in the optical absorption spectra of C60 and C70 are theoretically investigated by using a tight binding model with long-range Coulomb interaction and bond disorder. Anisotropy effects in C70 are also considered. Optical spectra are calculated by using the Hartree-Fock approximation followed by the configuration interaction method. The main conclusions are as follows: (1) The broad peaks at excitation energies, 3.7eV, 4.7eV, and 5.7eV, observed in experiments of C60 molecules in a solution are reasonably described by the present theory. Peak positions and relative oscillator strengths are in overall agreement with the experiments. The broadening of peaks by lattice fluctuations is well simulated by the bond disorder model. (2) The optical gap of C70 is larger when the electric field of light is parallel to the long axis of the molecule. The shape of the frequency dispersion also depends on the orientation of the molecule. These properties are common in the free electron model and the model with Coulomb interactions. (3) The spectrum of C70 averaged over bond disorder and random orientations is compared with experiments in a solution. There is an overall agreement about the spectral shape. Differences in the spectra of C60 and C70 are discussed in connection with the symmetry reduction from a soccerball to a rugbyball.Comment: PACS numbers: 78.66.Qn, 78.20.Dj, 71.35.+z, 31.20.Tz; LaTeX, 15 pages, 5 figures (Physical Review B); Note: Please request figures to Authors. They will be sent via snail mai

Applications of the RHIC AC Dipoles and Their Expected Performance

Two AC dipoles with horizontal and vertical oscillating magnetic fields will be installed in RHIC. They will provide coherent oscillations for beam dynamic studies and betatron function measurements. The AC dipole with horizontal magnetic field will also be used to induce a full spin flip for RHIC polarized proton experiments. This note discusses the applications of the AC dipoles in RHIC and their expected parameter

Stabilization of the Plate Current in Vacuum Tube Power Amplifier Using Cathode Resistor

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4-[(Dimethyl­amino)methyl­idene]-2-(4-nitro­phen­yl)-1,3-oxazol-5(4H)-one

The title mol­ecule, C12H11N3O4, is essentially planar, the r.m.s. deviation for all non-H atoms being 0.068 Å. An intra­molecular C—H⋯N hydrogen bond occurs. The crystal packing is dominated by π–π inter­actions [shortest centroid–centroid distance = 3.6312 (16) Å], which lead to supra­molecular chains that are linked into a three-dimensional network via C—H⋯O contacts. The crystal was found to be a non-merohedral twin (twin law −1 0 0/0 −1 0/ 0.784 0 1), the fractional contribution of the minor component being approx­imately 22%

Effects of acute sleep loss on leptin, ghrelin, and adiponectin in adults with healthy weight and obesity: a laboratory study

ObjectiveThis study investigated whether blood concentrations of leptin, ghrelin, and adiponectin are affected by acute total sleep deprivation in a sex- and weight-specific manner. MethodsA total of 44 participants (mean age 24.9 years; 20 women; 19 with obesity) participated in a crossover design, including one night of sleep deprivation and one night of sleep in the laboratory. After each night, fasting blood was collected. ResultsAfter sleep deprivation, fasting levels of leptin were lower (mean [SE], vs. sleep: 17.3 [2.6] vs. 18.6 [2.8] ng/mL), whereas those of ghrelin and adiponectin were higher (839.4 [77.5] vs. 741.4 [63.2] pg/mL and 7.5 [0.6] vs. 6.8 [0.6] mu g/mL, respectively; all p < 0.05). The changes in leptin and adiponectin following sleep loss were more pronounced among women. Furthermore, the ghrelin increase was stronger among those with obesity after sleep loss. Finally, the sleep loss-induced increase in adiponectin was more marked among normal-weight participants. ConclusionsAcute sleep deprivation reduces blood concentrations of the satiety hormone leptin. With increased blood concentrations of ghrelin and adiponectin, such endocrine changes may facilitate weight gain if persisting over extended periods of sleep loss. The observed sex- and weight-specific differences in leptin, ghrelin, and adiponectin call for further investigation.Radiolog