2,455 research outputs found
Estimating the Lunar Core Equatorial Ellipticity using Lunar Laser Ranging
No abstract availabl
British Association for Sexual Health and HIV national guideline for the management of infection with Mycoplasma genitalium (2018)
The pitfalls of plural valuation
This paper critically examines the current political context in which valuation studies of nature are undertaken. It challenges the belief that somehow, more and technically better valuation will drive the societal change toward more just and sustainable futures. Instead, we argue that current and proposed valuation practices risk to continue to overrepresent the values of those who hold power and dominate the valuation space, and to perpetuate the discrimination of the views and values of nondominant stakeholders. In tackling this politically sensitive issue, we define a political typology of valuations, making explicit the roles of power and discrimination. This is done to provide valuation professionals and other actors with a simple framework to determine if valuation actions and activities are constructive, inclusive, resolve injustices and enable systemic change, or rather entrench the status quo or aggravate existing injustices. The objective is to buttress actors in their decisions to support, accept, improve, oppose, or reject such valuations
Five steps towards transformative valuation of nature
The Values Assessment (VA) of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services shows that while a wide range of valuation methods exist to include nature's values in diverse decision-making contexts, uptake of these methods remains limited. Building on the VA, this paper reviews five critical steps in the evaluation of project or policy proposals that can improve the inclusion of nature's values in decisions. Furthermore, improving valuation practice requires guidelines that utilise quality criteria for valuation of nature and ensure a balance between them. This paper proposes three such quality criteria: relevance, robustness and resource efficiency. The paper argues that the five steps and three Rs can generate a practical checklist to support commissioning, evaluation and performance of more plural valuations. Such guidelines can provide the next steps needed to improve uptake of nature valuation in decision-making
Distribution of Aortic Root Calcium in Relation to Frame Expansion and Paravalvular Leakage After Transcatheter Aortic Valve Implantation (TAVI):An Observational Study Using a Patient-specific Contrast Attenuation Coefficient for Calcium Definition and Independent Core Lab Analysis of Paravalvular Leakage
BACKGROUND: Calcium is a determinant of paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI). This is based on a fixed contrast attenuation value while X-ray attenuation is patient-dependent and without considering frame expansion and PVL location. We examined the role of calcium in (site-specific) PVL after TAVI using a patient-specific contrast attenuation coefficient combined with frame expansion. METHODS: 57 patients were included with baseline CT, post-TAVI transthoracic echocardiography and rotational angiography (R-angio). Calcium load was assessed using a patient-specific contrast attenuation coefficient. Baseline CT and post-TAVI R-angio were fused to assess frame expansion. PVL was assessed by a core lab. RESULTS: Overall, the highest calcium load was at the non-coronary-cusp-region (NCR, 436 mm(3)) vs. the right-coronary-cusp-region (RCR, 233 mm(3)) and the left-coronary-cusp-region (LCR, 244 mm(3)), p < 0.001. Calcium load was higher in patients with vs. without PVL (1,137 vs. 742 mm(3), p = 0.012) and was an independent predictor of PVL (odds ratio, 4.83, p = 0.004). PVL was seen most often in the LCR (39% vs. 21% [RCR] and 19% [NCR]). The degree of frame expansion was 71% at the NCR, 70% at the RCR and 74% at the LCR without difference between patients with or without PVL. CONCLUSIONS: Calcium load was higher in patients with PVL and was an independent predictor of PVL. While calcium was predominantly seen at the NCR, PVL was most often at the LCR. These findings indicate that in addition to calcium, specific anatomic features play a role in PVL after TAVI
State preparation of a fluxonium qubit with feedback from a custom FPGA-based platform
We developed a versatile integrated control and readout instrument for
experiments with superconducting quantum bits (qubits), based on a
field-programmable gate array (FPGA) platform. Using this platform, we perform
measurement-based, closed-loop feedback operations with
platform latency. The feedback capability is instrumental in realizing active
reset initialization of the qubit into the ground state in a time much shorter
than its energy relaxation time . We show experimental results
demonstrating reset of a fluxonium qubit with fidelity, using a
readout-and-drive pulse sequence approximately long.
Compared to passive ground state initialization through thermalization, with
the time constant given by , the use of the
FPGA-based platform allows us to improve both the fidelity and the time of the
qubit initialization by an order of magnitude.Comment: 3 pages, 2 figures. The following article has been submitted to the
AIP Conference Proceedings of the Fifth International Conference on Quantum
Technologies (ICQT-2019
Quantum Nondemolition Dispersive Readout of a Superconducting Artificial Atom Using Large Photon Numbers
Reading out the state of superconducting artificial atoms typically relies on dispersive coupling to a readout resonator. For a given system noise temperature, increasing the circulating photon number in the resonator enables a shorter measurement time and is therefore expected to reduce readout errors caused by spontaneous atom transitions. However, increasing is generally observed to also monotonously increase these transition rates. Here we present a fluxonium artificial atom in which, despite the fact that the measured transition rates show nonmonotonous fluctuations within a factor of 6, for photon numbers up to ≈200, the signal-to-noise ratio continuously improves with increasing . Even without the use of a parametric amplifier, at =74, we achieve fidelities of 99% and 93% for feedback-assisted ground and excited state preparations, respectively. At higher , leakage outside the qubit computational space can no longer be neglected and it limits the fidelity of quantum state preparation
Quantum non-demolition dispersive readout of a superconducting artificial atom using large photon numbers
Reading out the state of superconducting artificial atoms typically relies on
dispersive coupling to a readout resonator. For a given system noise
temperature, increasing the circulating photon number in the
resonator enables a shorter measurement time and is therefore expected to
reduce readout errors caused by spontaneous atom transitions. However,
increasing is generally observed to also increase these transition
rates. Here we present a fluxonium artificial atom in which we measure an
overall flat dependence of the transition rates between its first two states as
a function of , up to . Despite the fact that we
observe the expected decrease of the dispersive shift with increasing readout
power, the signal-to-noise ratio continuously improves with increasing
. Even without the use of a parametric amplifier, at , we
measure fidelities of 99% and 93% for feedback-assisted ground and excited
state preparation, respectively.Comment: typos corrected, added figure at p.10 (section IV of the Supplemental
Material), added reference
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