Survival of entanglement in thermal states

We present a general sufficiency condition for the presence of multipartite entanglement in thermal states stemming from the ground state entanglement. The condition is written in terms of the ground state entanglement and the partition function and it gives transition temperatures below which entanglement is guaranteed to survive. It is flexible and can be easily adapted to consider entanglement for different splittings, as well as be weakened to allow easier calculations by approximations. Examples where the condition is calculated are given. These examples allow us to characterize a minimum gapping behavior for the survival of entanglement in the thermodynamic limit. Further, the same technique can be used to find noise thresholds in the generation of useful resource states for one-way quantum computing.Comment: 6 pages, 2 figures. Changes made in line with publication recommendations. Motivation and concequences of result clarified, with the addition of one more example, which applies the result to give noise thresholds for measurement based quantum computing. New author added with new result

The uses and functions of ageing celebrity war reporters

This article starts from the premise that recognition of professional authority and celebrity status depends on the embodiment and performance of field-specific dispositional practices: there’s no such thing as a natural, though we often talk about journalistic instinct as something someone simply has or doesn’t have. Next, we have little control over how we are perceived by peers and publics, and what we think are active positioning or subjectifying practices are in fact, after Bourdieu, revelations of already-determined delegation. The upshot is that two journalists can arrive at diametrically opposed judgements on the basis of observation of the same actions of a colleague, and as individuals we are blithely hypocritical in forming (or reciting) evaluations of the professional identity of celebrities. Nowhere is this starker than in the discourse of age-appropriate behaviour, which this paper addresses using the examples of ‘star’ war reporters John Simpson, Kate Adie and Martin Bell. A certain rough-around-the-edges irreverence is central to dispositional authenticity amongst war correspondents, and for ageing hacks this incorporates gendered attitudes to sex and alcohol as well as indifference to protocol. And yet perceived age-inappropriate sexual behaviour is also used to undermine professional integrity, and the paper ends by outlining the phenomenological context that makes possible this effortless switching between amoral and moralising recognition by peers and audiences alike

Demonstration of Einstein-Podolsky-Rosen Steering Using Hybrid Continuous- and Discrete-Variable Entanglement of Light

Einstein-Podolsky-Rosen steering is known to be a key resource for one-sided device-independent quantum information protocols. Here we demonstrate steering using hybrid entanglement between continuous- and discrete-variable optical qubits. To this end, we report on suitable steering inequalities and detail the implementation and requirements for this demonstration. Steering is experimentally certified by observing a violation by more than 5 standard deviations. Our results illustrate the potential of optical hybrid entanglement for applications in heterogeneous quantum networks that would interconnect disparate physical platforms and encodings

Analysis of the Nucleotide Sequence of the Treehopper-Transmitted Geminivirus, Tomato Pseudo-Curly Top Virus, Suggests a Recombinant Origin

AbstractThe genome of tomato pseudo-curly top virus (TPCTV), originating from Florida, has been cloned and sequenced. TPCTV is the only geminivirus identified with a vector specificity which falls outside the Cicadellidae (leafhoppers) and Aleyrodidae (whiteflies). Infectivity of the cloned viral genome was demonstrated byAgrobacterium-mediated inoculation of several host species. Progeny virus was transmissible by the treehopper vector of TPCTV,Micrutalis malleifera(Fowler). The genome of TPCTV shows features typical of both subgroups I and III genera of the family Geminiviridae. The coat protein of TPCTV, although distinct from all previously characterized geminiviruses, exhibits features more akin to the leafhopper-transmitted geminiviruses than those transmissible by the whiteflyBemisia tabaciGenn. The relationship of TPCTV to other geminiviruses, particularly beet curly top virus, is discussed in relation to the possible evolutionary origins of this virus

Opening up the Quantum Three-Box Problem with Undetectable Measurements

One of the most striking features of quantum mechanics is the profound effect exerted by measurements alone. Sophisticated quantum control is now available in several experimental systems, exposing discrepancies between quantum and classical mechanics whenever measurement induces disturbance of the interrogated system. In practice, such discrepancies may frequently be explained as the back-action required by quantum mechanics adding quantum noise to a classical signal. Here we implement the 'three-box' quantum game of Aharonov and Vaidman in which quantum measurements add no detectable noise to a classical signal, by utilising state-of-the-art control and measurement of the nitrogen vacancy centre in diamond. Quantum and classical mechanics then make contradictory predictions for the same experimental procedure, however classical observers cannot invoke measurement-induced disturbance to explain this discrepancy. We quantify the residual disturbance of our measurements and obtain data that rule out any classical model by > 7.8 standard deviations, allowing us for the first time to exclude the property of macroscopic state-definiteness from our system. Our experiment is then equivalent to a Kochen-Spekker test of quantum non-contextuality that successfully addresses the measurement detectability loophole

Celebrity culture and public connection: bridge or chasm?

Media and cultural research has an important contribution to make to recent debates about declines in democratic engagement: is for example celebrity culture a route into democratic engagement for those otherwise disengaged? This article contributes to this debate by reviewing qualitative and quantitative findings from a UK project on 'public connection'. Using self-produced diaries (with in-depth multiple interviews) as well as a nationwide survey, the authors argue that while celebrity culture is an important point of social connection sustained by media use, it is not linked in citizens' own accounts to issues of public concern. Survey data suggest that those who particularly follow celebrity culture are the least engaged in politics and least likely to use their social networks to involve themselves in action or discussion about public-type issues. This does not mean 'celebrity culture' is 'bad', but it challenges suggestions of how popular culture might contribute to effective democracy

Anesthesiology Resident Performance on the US Medical Licensing Examination Predicts Success on the American Board of Anesthesiology BASIC Staged Examination: An Observational Study

BACKGROUND: Correlation has been found between the US Medical Licensing Examination (USMLE) Step 1 examination results and anesthesiology resident success on American Board of Anesthesiology (ABA) examinations. In 2014, the ABA instituted the BASIC examination at the end of the postgraduate year-2 year. We hypothesized a similar predictive value of USMLE scores on BASIC examination success. METHODS: After the Committee for the Protection of Human Subjects at UTHealth Institutional Review Board approved and waived written consent, we retrospectively evaluated USMLE Step examination performance on first-time BASIC examination success in a single academic department from 2014-2018. RESULTS: Over 5 years, 120 residents took the ABA BASIC examination and 108 (90%) passed on the first attempt. Ten of 12 first-time failures were successful on repeat examination but analyzed in the failure group. Complete data was available for 92 residents (76.7%), with absent scores primarily reflecting osteopathic graduates who completed Comprehensive Osteopathic Medical Licensing Examination of the United States level examinations rather than USMLE. In the failure cohort, all 3 USMLE examination step scores were lower ( CONCLUSIONS: In anesthesiology residency training, our preliminary single-center data is the first to suggest that USMLE Step 1 performance could be used as a predictor of success on the recently introduced ABA BASIC Examination. These findings do not support recent action to change USMLE scoring to a pass/fail report

Work-Unit Absenteeism: Effects of Satisfaction, Commitment, Labor Market Conditions, and Time

Prior research is limited in explaining absenteeism at the unit level and over time. We developed and tested a model of unit-level absenteeism using five waves of data collected over six years from 115 work units in a large state agency. Unit-level job satisfaction, organizational commitment, and local unemployment were modeled as time-varying predictors of absenteeism. Shared satisfaction and commitment interacted in predicting absenteeism but were not related to the rate of change in absenteeism over time. Unit-level satisfaction and commitment were more strongly related to absenteeism when units were located in areas with plentiful job alternatives

Geometric Entanglement of Symmetric States and the Majorana Representation

Permutation-symmetric quantum states appear in a variety of physical situations, and they have been proposed for quantum information tasks. This article builds upon the results of [New J. Phys. 12, 073025 (2010)], where the maximally entangled symmetric states of up to twelve qubits were explored, and their amount of geometric entanglement determined by numeric and analytic means. For this the Majorana representation, a generalization of the Bloch sphere representation, can be employed to represent symmetric n qubit states by n points on the surface of a unit sphere. Symmetries of this point distribution simplify the determination of the entanglement, and enable the study of quantum states in novel ways. Here it is shown that the duality relationship of Platonic solids has a counterpart in the Majorana representation, and that in general maximally entangled symmetric states neither correspond to anticoherent spin states nor to spherical designs. The usability of symmetric states as resources for measurement-based quantum computing is also discussed.Comment: 10 pages, 8 figures; submitted to Lecture Notes in Computer Science (LNCS