2,804 research outputs found
Scalable simultaneous multi-qubit readout with 99.99% single-shot fidelity
We describe single-shot readout of a trapped-ion multi-qubit register using
space and time-resolved camera detection. For a single qubit we measure
0.9(3)x10^{-4} readout error in 400us exposure time, limited by the qubit's
decay lifetime. For a four-qubit register (a "qunybble") we measure an
additional error of only 0.1(1)x10^{-4} per qubit, despite the presence of 4%
optical cross-talk between neighbouring qubits. A study of the cross-talk
indicates that the method would scale with negligible loss of fidelity to
~10000 qubits at a density <~1 qubit/um^2, with a readout time ~1us/qubit.Comment: 4 pages, 3 figures; simulations added to fig.3, with some further
text and figure revisions. Main results unchanged
Phenomenology of B -> pi pi, pi K Decays at O(alpha^2 beta_0) in QCD Factorization
We study O(alpha^2 beta_0) perturbative corrections to matrix elements
entering two-body exclusive decays of the form B -> pi pi, pi K in the QCD
factorization formalism, including chirally enhanced power corrections, and
discuss the effect of these corrections on direct CP asymmetries, which receive
their first contribution at O(alpha). We find that the O(alpha^2 beta_0)
corrections are often as large as the O(alpha) corrections. We find large
uncertainties due to renormalization scale dependence as well as poor knowledge
of the non-perturbative parameters. We assess the effect of the perturbative
corrections on the direct CP violation parameters of B -> pi^+ pi^-.Comment: 27 pages, 5 figures. Updated input parameters and added citations;
expanded discussio
Life cycle stages, specific organelles and invasion mechanisms of Eimeria species
Apicomplexans, including species of Eimeria, pose a real threat to the health and wellbeing of animals and humans. Eimeria parasites do not infect humans but cause an important economic impact on livestock, in particular on the poultry industry. Despite its high prevalence and financial costs, little is known about the cell biology of these ‘cosmopolitan’ parasites found all over the world. In this review, we discuss different aspects of the life cycle and stages of Eimeria species, focusing on cellular structures and organelles typical of the coccidian family as well as genus-specific features, complementing some ‘unknowns’ with what is described in the closely related coccidian Toxoplasma gondii
Retrieval of patients with severe respiratory failure on venovenous extracorporeal membrane oxygenation: an intensivist-led model
Condensation of microturbulence-generated shear flows into global modes
In full flux-surface computer studies of tokamak edge turbulence, a spectrum
of shear flows is found to control the turbulence level and not just the
conventional (0,0)-mode flows. Flux tube domains too small for the large
poloidal scale lengths of the continuous spectrum tend to overestimate the
flows, and thus underestimate the transport. It is shown analytically and
numerically that under certain conditions dominant (0,0)-mode flows independent
of the domain size develop, essentially through Bose-Einstein condensation of
the shear flows.Comment: 5 pages, 4 figure
Apraxia and motor dysfunction in corticobasal syndrome
Background: Corticobasal syndrome (CBS) is characterized by multifaceted motor system dysfunction and cognitive disturbance; distinctive clinical features include limb apraxia and visuospatial dysfunction. Transcranial magnetic stimulation (TMS) has been used to study motor system dysfunction in CBS, but the relationship of TMS parameters to clinical features has not been studied. The present study explored several hypotheses; firstly, that limb apraxia may be partly due to visuospatial impairment in CBS. Secondly, that motor system dysfunction can be demonstrated in CBS, using threshold-tracking TMS, and is linked to limb apraxia. Finally, that atrophy of the primary motor cortex, studied using voxel-based morphometry analysis (VBM), is associated with motor system dysfunction and limb apraxia in CBS. Â Methods: Imitation of meaningful and meaningless hand gestures was graded to assess limb apraxia, while cognitive performance was assessed using the Addenbrooke's Cognitive Examination - Revised (ACE-R), with particular emphasis placed on the visuospatial subtask. Patients underwent TMS, to assess cortical function, and VBM. Â Results: In total, 17 patients with CBS (7 male, 10 female; mean age 64.4+/2 6.6 years) were studied and compared to 17 matched control subjects. Of the CBS patients, 23.5% had a relatively inexcitable motor cortex, with evidence of cortical dysfunction in the remaining 76.5% patients. Reduced resting motor threshold, and visuospatial performance, correlated with limb apraxia. Patients with a resting motor threshold <50% performed significantly worse on the visuospatial sub-task of the ACE-R than other CBS patients. Cortical function correlated with atrophy of the primary and pre-motor cortices, and the thalamus, while apraxia correlated with atrophy of the pre-motor and parietal cortices. Â Conclusions: Cortical dysfunction appears to underlie the core clinical features of CBS, and is associated with atrophy of the primary motor and pre-motor cortices, as well as the thalamus, while apraxia correlates with pre-motor and parietal atrophy
Reputation in European Trade Mark Law: A Re-examination
Under the harmonised European trade mark regime marks with a reputation enjoy expanded protection. This article casts doubt on whether this ‘reputational trigger’ can be justified. It then explores some difficult operational questions about the way the reputation threshold works in cases where the mark enjoys fame only in niche markets or in a limited geographical area, the aim being to illustrate further why reputation is an unsatisfactory trigger for a different type of trade mark protection. Finally, it looks at some of the evidential difficulties involved in adjudicating disputes in which expanded protection is being claimed. It concludes by suggesting that if the evidential problems we identify were tackled the reputation threshold could be abandoned
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